First of all Gizmo, let me apologize if I've offended you. It's not my intention.
You didn't offend me at all. I was referring to my experiences of how players would feel 99% of the time being involved in some of the interactions that you (and others) have advocated. I'm arguing against the suggestion because AFAICT that DMing style is rude. Suggesting or discussing the style is not rude IMO and I didn't mean to suggest it was.
The phrase "Common Sense" is an idiom. The meaning is not derived from either word or their logical combined whole, instead it is determined by a traditional meaning assigned by the majority of english speakers.
One English speaker (Mark Twain I think) said something to the effect that "common sense" is just biases that are internalized before the age of 12. I think he was suggesting a distinction between "conformity" and "wisdom".
The situation IMO requires that the DM respect the intentions of the players in the game. If he cannot, then the problem should be solved outside of the game. The concept of "common sense" in this case AFAICT seems to just diminish the opinions of persons who disagree with the DM in an unwarranted way, and is counterproductive. Otherwise, it's not useful because if it were truly common then there would be no need to debate the issue.
I'm not referring to some commonly held ideal, well... not directly anyway. But sufficient wisdom to realize that if a particular interpretation of the rules seems too good to be true, then it probably shouldn't be interpreted that way.
But, as I said, your use of "common sense" doesn't appear to be communicating *anything* directly that isn't a tautology. So the indirect (but obvious) interpretation here is that the player's opinion lacks reason.
In any case, it seems very likely that a player in this situation wouldn't find his interpretation of the rules to be "too good to be true" at all. The "too good" part of this is the DMs bias. It's not "too good to be true" that I'm able to use an axe to chop down a wooden door. Nor do I care to speculate why NPCs haven't thought of this before me. Your wisdom, AFAICT is really heavily dependant on a particular view point that is entirely subjective.
I don't think that the DM's job is to enforce their opinions upon the game.
I'd rather the DM enforce his opinion on the game than on my sense of reason. IMO it's important to note here that what we're talking about is largely a matter of interpersonal relationships and people sharing a hobby. In that way the DM is not "superior" to anyone else (as I think you agree). As a result, it's much more fair to say "I don't allow halfling PCs in my game" than it is to say "you, as a player, are showing a lack of common sense for wanting to play a halfing in my game".
In any case, I meant to say "incorporate" (and I think I did) rather than "enforce". And "incorporate" means that the normal etiquette of house ruling is followed. If I want to run an "Arthurian knights" type of game, it's fair for me to adjust the game's rules so that "Arthurian knight" type technologies and problem-solving strategies are dominant. Not expect the players to guess at what my opinion is about those things.
The DM is an elected official, of a sort, entrusted by a group of players with authority and responsibility to adjudicate the rules on their behalf.
And in the process of doing so imply that the very people that have entrusted him with this resonsibility lack common sense? I know that's not what you intend by your suggestion, but I think that would be the unintended consequence. (And one I've observed when this DMing method has been employed).
This does not mean that I think anyone who disagrees or finds the 'spellcasters only' argument more persuasive lacks "common sense".
But if someone says (as an extreme example. This is not meant to typify your viewpoint as a strawman, or to invoke some kind of slippery slope argument. This is for illustrative purposes only)...
As I was saying, if someone says "But it never says you can no longer take actions after you die, therefore my character can", then I would describe that as lacking "common sense".
But there are two different approaches here. The one you use in your actual game I agree with. The other (and I'm not sure what it's illustrating) is not. In any case, the key conditions that your second example set up are not at issue here.
Take for example a player saying "my character should be able to act after he dies.". This example fails to be a good analogy in a number of respects. The most important one is that there's nothing in the rules that logically implies this. This rule is completely of the player's own devising. In the case of the war dogs or alchemists fire, this is definitely not the case. The prices are given. The stats are given. The DM just simply doesn't like the results. If the case were as simple as the revenant example you give, the DM would not be experiencing heartburn. IMO it's that the players have a pretty good case for their action that causes the DM his reaction.
The OP was not trying to solicit advise on how to handle a player that wants his character to continue to act after death (or anything as comparably simple). And so here the devil is in the details.
While we disagree, sometimes a great deal, it is not because they lack common sense... at least not in my opinion. We merely have different ideas.
Some ideas though seem to me to lack common sense.
At this point in your post I'm not sure we disagree about anything. I'm sympathetic with the idea that in a constructed, extreme situation a player's suggestion (like anyone elses) could lack "common sense". However, I don't really see how it applies to the examples given (alchemist's fire, war dogs) which are pretty solidly based on rules (which is really the problem the DM is having, otherwise, the problem is easily solved).