I'm not going to respond point by point in the interest of keeping it civil, and becuase I think I'm just repeating my main point ad nauseum right now.
I share the problem with whiney players crying when they can't get their specific case in a certain campaign and demand it unflinchingly. However, I have the exact same problem with the other side of the cardboard screen, too. It works both ways. Just as players won't be welcomed to my game if they cry and complain about their specific character and how you suck if you're not giving it to them, DM's won't be welcomed to my game if they are arbitrary, heavy-handed, and condescending, with more interest in their own story than in making the group have fun.
I'm reasonably sure everyone can agree on that.
Now, the books needed to play D&D are the baseline, especially the PH. This is the instruction manual for playing D&D, just like that little pamphlet you get with Monopoly is the instruction manual for playing Monopoly. The two share another similarity: they encouarage you to play with the rules themselves, to change the way the game is played. A majority of DM's change the way the "D&D game," as presented in the Core Rules, is played. Just like I think I'd be hardpressed to find any family that plays Monopoly the way the manual says (y'know, without the Free Parking Fund). It's not any worse, but it is a change. It is an alteration. It is a House Rule. It might make the game better, it might just change the way it's played, but it's all a House Rule. It's not the way the game was *designed* to be played, but it's no less a *valid* way to play it. If someone plays without Chance cards, or if the DM allows antimatter rifles, these are house rules. There is an instruction manual.
Now, here's where it gets into things that are not generally fairly objective realities. And here may be the part where I part ways with some people, but also what I think may be part of the cause behind this much-decried "third edition culture" that is being bemoaned here.
Say, one family plays Monopoly with one dice, instead of two. Say one DM plays without halfling rangers. These are both house rules. They're changes from the norm. They both remove something that is in the instruction manual. Ditch it, nix it, boil it alive in a pot of acid, whatever you wanna say.
If the family was looking for people to play Monopoly with (putting up flyers at the local Kay-Bee Toys), I don't think "So, why only one dice?" is some volatile question. You read the manual, you expect two dice, so when there is only one, you deserve to know why they're changing it There are thousands of things they could say in response. "We lost one." "Beacause it means more properties get baught up earlier, and we enjoy the period of the game when everybody owns stuff to the pre-buying stage." "Because two dice is just too many to hold in your hand." " Because math is hard."
Of course, if the potential player is really attatched to two dice for some reason (say, he likes the clicking noise they make when he rolls, which one die just doesn't do), there are only two really narrowminded options, and a host of potentially accepting ones.
Family: "Because that's the way it is, that's the way it has been, and that's the only way we like it, and if you don't like it, too bad, it's our game, you go pout over there if you want two dice you stupid math-lover!" (narrowminded, though still valid).
Player: "You've gotta use two dice! If you don't, you're not playing real monopoly! I can't believe you'd break the rules like that! It says you use two dice here in the manual! You've gotta use two dice! Or at least let me do it! Come on, adding is totally awesome!" (narrowminded, but also valid)
Player: "Hu...well, I agree math is hard, but I'd like the game to last a little longer. I've got a d8 here, can we use that instead of a d6?" (one of the many potentially accepting ones).
Player: "Okay, whatever, let's just play." (one of the most common responses)
Player: "Sorry, I love math, I don't think I'd have a lot of fun in your game. Good luck finding a player." (another very common response)
Similarly, if the DM is looking for people to play D&D with (putting up flyers at the FLGS), I don't think "Why no halfling rangers?" is beyond the scope of questions that the DM should have to answer. You read the manual, you know halfling rangers are allowed, so when you can't be one, you deserve to know why they're changing it. There could be thousands of responses. "Halfling rangers are overpowered." "Only munchkin rollplayers like halfling rangers." "The culture of halflings in my campaign have never been outside of the major city." "Halflings are gypsies, not woodsmen."
Of course, if the player is particularly attatched to halfling rangers for some reason (the concept of a halfling sling-archer is appealing to him), there are only two really narrowminded options, and a host of potentially accepting ones.
DM: "That's the way we play this game, that's the way it is, and that's the way it always has been, I'm not going to move for you or anyone else. I am the DM, and I say no halfling rangers, so forget it. You're playing in my game, and what I say goes." (narrowminded, though still valid).
Player: "No halfling rangers?! What are you thinking?! I can't live without my midget wooodsmen! How will I ever have my drow have a halfling ranger dipped in black paint so I can call him mini-me! The book says there are halfling rangers, and you have to obey the laws!" (narrowminded, though still valid).
Player: "Okay, can I change all of a ranger's wilderness abilities to city-based abilities and play an urban halfling ranger?" (one of the many potentially accepting ones).
Player: "Okay, whatever, let's just play." (one of the most common responses)
Player: "Y'know, I'm not sure I'd fit in with a group that thinks halfling rangers are a representative of munchkin rollplaying. Sorry, but good luck." (another very common response)
So there it is. Just as I don't think players should wave the core rules in a DM's face and demand they accept it, I don't think DM's should wave their house rules in a player's face and demand they accept it. The only difference is that the DM has a trump, so to speak. Many players rightfully fear the DM who pulls out that trump on every occasion as if it was their first taste of power in the world, just like many DM's rightfully fear the 'rules lawyer.' But a DM who uses that trump only to help shape their setting is a good DM, just like a player who uses the rules to aid the story of their character is a good player.