Sure. If the premise doesn't sound fun to me, I won't bite. I've passed over applying to numerous games over the years because the pitch, premise, or limitations just weren't my speed. (As an example, I genuinely don't understand the point of trying to play low-power PF1e unless it's E6, and E6 doesn't appeal to me, so any PF1e game that is predicated on either idea I just won't even look at.)
Sure. That's precisely the process of having a sincere conversation should do. It is possible, though I think it should be quite rare, that genuinely no resolution can come out of it. Hence why I heavily raise an eyebrow when people declare, without any discussion in advance, that no it absolutely couldn't be possible and you'd better get used to it.
Personally, I think having a diverse range of options is all to the good. Not only does that mean you have significantly more valid subsets to work with, but it's also a lot more likely that even if options A, B, and C are out, your players will be content with something from options D-J instead. There are certainly limits; as I've said before, I think there's somewhere between 18 and 25 class fantasies that D&D more or less supports (specific things, mind; it's not a ranked list, but it is one particular list). Having that many classes to draw on enables an enormous variety of specifically-themed worlds by selecting subsets.
Of course, I would also prefer that instead of the game making ridiculous and false blanket statements (like the idea that every fantasy world always has humans, elves, dwarves, and halflings, which the 5.0 PHB either outright says, for humans, or strongly implies, for the other three), the books instead go over both advice and examples for how class and race selections produce a particular campaign feel.
A setting where the only explicitly supernatural classes are Psion, Assassin, Artificer, and Monk, and the other classes are "Machinist" (not my favorite name but it's my current placeholder), Warlord, Rogue, Fighter, and Barbarian? That's a fascinating world concept, one where obscure magic and occult phenomena are much more prevalent and involved than the usual spells we think of, which implies perhaps a more Lovecraftian bent, or maybe a Westeros-style thing where magic limitedly exists but is resurging, etc. Likewise, a setting where (say) humans were only recently introduced, and the dominant species are satyrs, wemics, kobolds, and changelings? That's bound to look quite, quite different from the bog-standard everyone's-seen-it-a-million-times superficially-Tolkienesque knockoff.
I absolutely agree that curation of a setting can produce extremely interesting results. I just find that a lot of DMs-arguing-on-the-internet have a "vision" that is little more than that: a superficial Tolkien knockoff.
