Since this comparison has been brought up, let's look at the lore behind things, as well as appearance:
A Yuan-Ti cannot pass for human, and close scrutiny is going to happen if the Yuan-Ti is walking among other societies, or they will be attempting to hide these hints, which will likely be suspicious.
And then,
if the Yuan-Ti is a known race in a world, the whole second part about infiltration and kidnapping/ sacrificing others would probably lean towards an open hostility by those others.
So, yeah, a Yuan-Ti PC in my game world will be treated with suspicion if not open hostility if discovered. Which is why I would tell the player, go ahead, but your PC will have the same issues among most civilized lands as a Drow elf would. I've had players accept the "Drow" challenge and embrace it, and I would hope if the player
really wanted to be a Yuan-Ti that badly, they would accept it as well. If not, they are always free to play something else or join a different group.
I am not going to change the lore of Yuan-Ti in my world (which they are, just not PC playable unless the player accepts that challenge) to make the experience "easy" simply because a player wants to play one when there are many other choices. The same goes for other "monstrous humanoid" races (goblins, orcs, etc.), which are generally at odds (at the very least) with the playable races in the game.
Now, to be clear, players
can encounter individuals who struggle against the norm of their species/culture (such as Finn the ex-stormtrooper in the newer SW movies), or even entire groups (such as the other ex-stormtroopers Finn and the others meet on Endor's moon). But that is the players' choice to engage/accept such individuals or groups, and sometimes I have more "accepting" NPCs when players do play Drow, but they understand that will not generally be the case.
Now, for the other side:
Are all elves universally accepted? Of course not! If a player has an elf PC (especially one with a strong personality, i.e. high Charisma) sometimes they are treated by others with caution as their "haunting" beauty makes that NPC uneasy. Elves are often treated coldly due to their own haughty nature. There is always the general distrust of strangers when an elf enters an area with those living their have rarely (if ever) encountered an elf.
I like using "reaction rolls" to determine most often how NPCs will react, and that can be bad or good, depending on the interaction. But by-and-large, elf culture and people (other than Drow, of course) are known of as being kind, willing to negotiate, and peaceful--even if high-minded and lofty.
At any rate, if that is contrary to others' sensibilities, I'm sorry for that, but I have just as much right to run my game world as I think works best, including my reasons for restricting playable races or races even existent in the game, as others who want to run a more communal world and let players do more or less as they want.