Some of my heavy criticism here is due to my experience with my players. Even though I have told them outright (as part of Session Zero) that I find permanent, irrevocable, random death* both boring and wasteful, and will not use it in my game, they are still very, very cautious almost all of the time. They look for ways to maximally reduce risk and increase safety, and may completely ignore danger if they can't manage the risk sufficiently....even when doing so is clearly unwise. So I have to respond to that group style. Doing things that sharply discourage taking risks is simply ineffective for my group; it makes them turtle up, becoming extremely passive and reactive rather than active and proactive. Hence, I recognize that some of the dispute here is purely group context. I favor environments that encourage openness to player ideas even if that means not enforcing every plausible negative consequence, and familiars are just one aspect like that.
But there is a broader sense in which I see the openly hostile approach as reflecting a common trend I see in D&D, tabletop, and even video gaming: perverse incentives. There are a lot of games (be it home D&D campaigns, MMMORPGs, board games, whatever) which undermine their own goals by providing incentives they think are positive but are not. This sort of problem can be really, really difficult to spot, even with people trying to avoid it. As an example, there was a thread here a couple years back IIRC, where a DM had gotten incredibly, unbelievably frustrated that his players were CONSTANTLY going into murderhobo mode in almost every social encounter that wasn't either completely obviously "if you fight you're going to die" or "these are 100% unequivocal allies that have no interest in fighting you." For the longest time, they couldn't figure out why their players kept doing this, until they discovered that the players all thought it was what was expected of them, and said players had, themselves, gotten deeply frustrated and even upset about thinking they HAD to fight all the time...because
the DM kept bringing out a map. IOW, the DM thought they were adding realism and immersion, but they were instead accidentally adding an incentive nobody actually liked and that was actually damaging the health of the game, but no one realized these results were not what the group NOR the DM wanted.
I do not give this example to say that it MUST be happening every time groups do things I don't. That's why I opened with what I did. I understand that each group is its own context and does not need to work like mine does. Some groups are...shall we say irrationally exuberant. Others love to push boundaries no matter what. Some, like mine, need encouragement before they will take any risks, while others are more balanced and thus need neither special incentives nor special consequences.
I give this example, rather, to say that it is very easy to THINK things are going well when they are not. That it is necessary to be constantly vigilant for DM errors of judgment of simply of presentation, errors that may go completely unnoticed unless the DM proactively and consistently hunts down feedback. Experimenting is often extremely important, sometimes even necessary. Positive evidence alone cannot guarantee you have the right path.
There's a common math/logic "puzzle" designed to show this: you ask individual volunteers to pick numbers and you tell them if their guess fits the pattern you're thinking of, and they must try to figure out the pattern. Most people start by guessing "one," and you tell them no; they then guess "two" and you say it fits. They then keep guessing even numbers and all the even numbers work, so they assume it must be ONLY even numbers...but the rule is just "a number bigger than 1" or something else not exclusive to even numbers. Most humans never check for
disproof of their theories, only looking for the presence of positive evidence, not the absence of negative evidence. In many cases, ignorance about negative evidence blinds us to the true state of affairs because we've never allowed for the possibility.
Hence, it is often very useful to test the opposite of one's theories to see if they hold false when one expects them to hold false. Sometimes such testing is not workable. E.g., I'm not going to make my game lethal to test whether my players would become more willing to take risks, as I already have enough evidence that getting them to take even
critically necessary risks can be very difficult. I already know what those results will be from experience: adding lethal dangers, even when my players have precautions against those dangers, makes them pull away. But I endeavor to experiment and expand my methods. I try to keep my eyes and ears open and to test myself against things I would normally avoid. I'm something of a softie DM, so I have intentionally thrown overpowered encounters at my party to see where their power level tapped out. I have tried methods and (sub)systems that are not my preference, but that might be my players' preference. Etc.
As a result...
The question I would have is why you seem to look at this as a punishment for familiars and not just another meaningful choice a player makes in the context of the game. I find it unusual for someone to look at having to make meaningful decisions as "piling on difficulties" or that no consideration is given for the "fun part of it from the players' side." Do you imagine my players aren't having fun with this? Two PCs in the current party have familiars. I imagine if it was so terrible they wouldn't.
You have shown they are willing to tolerate it. That is not, in and of itself, evidence that they like it. I think we agree that in order to like something, one must tolerate it, but one can tolerate something without liking it. It is a necessary condition, but not a sufficient one.
As for the question: Because those consequences do not sound fun or entertaining or enriching to me. They sound like you have started from a position (as implied by your second post) that familiars are bad and should be taken away from players as soon as possible. All consequences arising from the behavior of creatures in the world are the DM's choice and responsibility. These examples read, to me, like fishing for the most negative consequences you can muster, so that any advantages potentially gained from a familiar are at least equalled and often exceeded by the risks. When the risks are substantial and everpresent, the rewards minimal or non-existent, and you make such a major point out of how even a
single hour is a dramatic and often untenable cost, particularly coupled with your explicit "kill on sight" attitude, it doesn't sound like you're trying to offer a rich experience where choices matter and resources must be managed. It sounds like you've already decided that the familiar is a
bad choice and should be given the bad consequences (or, more simply,
punished) accordingly.
Making such a point to emphasize how hostile you will behave toward player familiars and how difficult, perhaps even impossible, it will be to ever restore them communicates a disinterest in the enthusiasm of your players. That is, it sounds like they will take the consequences you offer and enjoy them, or leave. That kind of "my way or the highway" attitude is both a pernicious problem in D&D gaming and an easy trap to fall into for anyone in a position with as much authority as a DM has over their game. I take very, very seriously evidence suggesting the presence of such attitudes, and critique them heavily wherever they even seem to appear.
Or you didn't get the joke.
At no point in this entire thread have you even remotely appeared to be joking. Especially not the post where you said that your policy is to kill familiars on sight if given the opportunity. Nothing in that post, nor in the posts that have come after, suggested even a hint of sarcasm or tongue in cheek. If your intent was to tell a joke, not only has it misfired badly, but you REALLY should have either recognized that tone is incredibly hard to convey over text, or you should have said so much, much earlier. Like, maybe as soon as it seemed people were taking seriously something you meant to be taken humorously.
So, what part of your positions has been a joke thus far? I am honestly asking because I literally have no idea what is supposed to be humor here and what is supposed to be serious.
*Brief note, every single one of the words in the phrase "permanent, irrevocable, random death" is chosen carefully. Permanent death is contrasted with, say, being dead for a time before automatically returning to life. An irrevocable death is one that cannot be reversed by later actions. And random is, as one might guess, something unplanned, the unexpected and usually unwanted result of a die roll or other unpredictable event. Deaths may be permanent and irrevocable but not random, or permanent and random but not irrevocable, or (rarely) irrevocable and random but not permanent (e.g. they WILL come back to life but they cannot hasten said revival.) No PCs have died in my game yet, but if any do, it will either be player choice to stay dead, or used as a tool for driving further adventures with and around that character.