Nice job assuming that I as a person am bigoted just because I prefer details that contribute to the story. I'm fine with people being different, that's a fact of life, and any self-respecting person should figure out how to accept that as soon as possible. What I look for in a roleplaying game, however, is narrative cohesion, where the characters are characters instead of tokens, and their actions have consequences that make sense. Mechanically, this means that I would prefer to not be held back by my fellows, be it the guy playing a Wild Magic Sorcerer who insists on triggering a Surge via Feywild shard whenever possible and gets sad when it doesn't go off, or the guy playing a Wizard that insists on hobbling up the stairs on their crutch instead of letting the Barbarian carry them. This doesn't mean it can't be done well ever, I've had an old man NPC with a halved movement speed use that as a way to get the party to pay attention to their surroundings instead of rushing headlong into a hallway just because it's empty. It should be in a way that doesn't impact gameplay; a one-armed Fighter wouldn't insist on one-handing a Halberd under normal circumstances and would usually go for a one-handed weapon, nor would a character that's been mute their whole life have a very good way to cast spells with verbal components without a kind DM or an addiction to Subtle Spell. Narratively, it means that things feel strange when someone opts to "have a disability" but then avoids playing into that angle at all by having a proverbial "all-terrain wheelchair" work-around with few downsides, possibly some benefits. Again, not that they can't ever be well-represented. The trick is that you need to make up for the character's weaknesses in a way that doesn't make them "speshul" by being the only one allowed to have that thing.

"Why would you guys want a cane-sword that doubles your movement speed? You don't have gammy legs halving your movement speed!" A cane-sword that doubles movement speed is still a weapon that doubles your god-damn movement speed. Don't "gatekeep" my characters from your cool idea without at least giving me a story as to why I can't have it (my character didn't make it and I don't know where the creator went) and how I could get to the point where I can if I wanted it (have to find the creator and convince them to make one for me even though I don't really need it like the first character does). Now, if they play a disabled character straight, taking efforts to minimize the mechanical detriments through tactical assessment of one's abilities and rely on the party to help make up for their weaknesses, congratulations! A character was made and I have no beef, you've won me over. If they miss some points, either expecting people to play around the character detriments they chose or playing Oppression Olympics™ as to why their character needs something your character can't have, because they decided the character would suck otherwise, that's just disingenuous to the multiplayer experience, and frankly kind of fucked up to hold one's own character hostage with disability to get preferential treatment. If your character is a Polearm Master Fighter that lost his arm in the war and is questing for a Regenerate spell as he goes through life with a spear and a dream, maybe even giving up on it as he realizes he can adapt to a different style of fighting bit by bit as he levels up, I welcome and endorse it.

Now, the character can hiss and spit about the unfairness of their situation until they're blue in the face, that's roleplay and I wholly support that in a roleplaying game. What's bad is, in the scenario the (N)PCs wise up to an item's necessity, any item, and in some way negate it, putting the player in a position where they need to play the character they made in a weaker position (in this case the weakness they built into it), the player shouldn't get upset over it. When the player insists that "their character's agency" shouldn't be lost because of losing one item, or "why did you approve it just to take it away?", broseph, you made the character. Did they genuinely think the party would thank them for being graced with the blast radius of a Wild Magic Surge, or are they just a gambling addict that couldn't foresee other people not wanting to be hit by the rebounding Chaos Bolt when there's only one enemy target? Is that sort of player incapable of realizing that the game system with mechanics to ensure it's not a make-pretend battle of "nuh-uh, I have [excuse] to protect me" could possibly allow for the other side to have counterplay in the same way they can make a magic chair that can climb a wall?

As for NPCs. Man, if these guys can't handle a one-eyed veteran in a fictional country, I fear for them ever seeing a homeless shelter. They need to sort their shit out. You can have a beggar in a D&D game, they might even be a good source of information or a powerful NPC that has problems, same with a person with a crutch or a leper on a wheeled board. Sorry we forgot to put "trigger warning: semi-accurate depictions of squalor" in Session 0's notes, if the existence in fantasy is what sets them off, I'd hate to see how they react to reality.

TL;DR: sometimes you can hate the player instead of the game. My beef is not with the existence of the differently abled, but with people that use them as a shield for their lack of originality, thought, or care for their fellow players.