Agreed, but there's also two other categories.
One is the "look at me!" guy, who wants to play something weird as a way of hogging the spotlight. Now every other player has to work their concepts around his, and the GM has to give him more attention as the world either reacts realistically to his unusual, super-special character or strains disbelief by ignoring it.
And the other is the player who just didn't care. They've got their tiefling cleric of Vecna, and that's what they're playing? Tieflings don't exist in the setting? Vecna doesn't exist in the setting? Eh, whatever, deal with it. They didn't give any thought to how such a character might plausibly exist in the world or the campaign the GM pitched, and they're not going to make any effort to try and make them feel like part of the world or story, purely because they didn't pay attention to anything about the world or the campaign pitch.
Again, should we just assume that is the case? I'm not saying such people don't exist, but it seems like every time this topic comes up it is the player who doesn't want to play a human/dwarf/elf/halfling that is the problem. They are attention hogs who don't care or min-maxxers who don't care or.... it is endless.
An earlier poster pointed out, there is nothing about gothic horror that prevents a cat person from being involved. The horror is coming from the actions being taken and their descriptions, not from the players staring across the table a cat. Also, the Mist very specifically is supposed to take people from across the multiverse, so, logically there is no reason it couldn't take a tabaxi.
Why is that player a problem who wants to be a snowflake, when they fit the story being told?
Even a major trade city in real world Victorian England would react extremely to a walking cat person, yes.
Sure, in real world anywhere a giant talking cat would get an extreme reaction.
In fantasy Victorian England where people from across the multiverse have been pulled by dark powers and eaten by monsters in the dark for centuries?
Somehow I don't think it is that strange they might have seen worse, upon occassion.
Bingo. Too many times I had players who want to have a waiver to play a special race/class/etc. Then get surprise when the town folk treat them with suspension. But we go with the Tabaxi in a world that they are super rare if they exist at all. Maybe the upper crust merchant who deals with magical items and crazy wizards would not bat an eye. But walk into the average bar and expect they just give you a hardy handshake, no.
It comes to play style. I treat pcs as they are people who showing up to help (maybe). This does not mean the townies are play kissy face with each pc. Other play styles include Mr. Spock just having a childhood accident when his head got caught in a rice picker and the npcs just don't bat an eye.
As a DM I will at session 0 give my elevator pitch. The players can accept or suggest changes. But if I say a hard NO to a change, the player either can play or sit out the sessions.
@doctorbadwolf seems to be on the side, the dm must always compromise their vision. Did that plenty of times. Did not enjoy it. Will not do again.
And now we are back at the DM compromising his vision. Again.
In my earlier example, somewhat riffing off the idea that "if even one players suspension of disbelief" was ruined that the character was not ok, I specifically didn't bring the DM into. They were neutral to the whole affair.
So, what if the DM isn't compromising his vision. What if he is fine with a Dragonborn Paladin because he wants to do some cool things with that. But another player starts going on about how Dragonborn make no sense in the setting. Is the Dragonborn player still the problem?
And, when you have townsfolk view the Tabaxi with suspicion and possibly hostility, do you make any consideration about the rest of the party? By that I mean, if elves and dwarves and halflings are all okay, and you have say A Human Cleric of the Goddess of Light, a Dwarven Paladin and an Elven Ranger whose people have helped the village in the past walking into town with a cat person... the townsfolk might be a little weirded out by a cat person, but they've got two divine forces of good and a local hero with them, so he can't be that bad.
In my experience, no, each party member is treated as a distinct unit, as though they are traveling alone and just happen to be sitting next to a local legend.