Well, they don't need to do all of them. Just the major types.
If they don't do all types, I'll hate the game. If you can't actually capture one of the most unique aspect of a fictional race in your game, then you shouldn't have wrote that part about them in the first place, simple as that.
But it's not actually impossible to do, the non-humanoid types could be implemented as "creatures", whereas the humanoid ones could be playable races, it would perhaps be time consuming, and add a bit more effort to designing and balancing races, but finally getting to see Khajiit live up to what's promised in the lore would be well worth it.
The potential problem is mostly a matter of taste. Elves and humans are generally more poular than cat-people (except maybe in Japan
) and when they do Elsewyr not only will the majority of NPCs be Khajiits, the majority of playable races will also be Khajiits.
Elves are stupid and fantasy has long svcked out whatever portential for creative ideas might have once existed in them like a vampire, Bethesda
tried, but the only way anyone could actually hope to create elves that are actually creative and interesting at this point is to make it so their hardly recognizable as elves, as all the interesting ideas you could do with them have already been done before, now talking cats, on the other hand, have not had too much of their potential exploited outside of their potential as cartoon characters and mascots.
Besides, we already have three too many types of elves and three more varieties of humans than we need, it hardly seems unreasonable to ask for a bit more variety in cat people as well.
Given that Beth totally threw in the towel when it came to giving Cat and Lizard people Cat and Lizard bodies in Oblivion, yes. I'd have to say that Bethesda would be completely incompetent at making TES: Elsewhere. (really, no pun). You know you've snorted too much coke when you've forgotten what your own game series is supposed to be about.
As much as I consider Oblivion's Khajiit and Argonians a step backwards from Morrowind, that's a little unfair, considering that in some ways, it's a step closer towards how things were in earlier Elder Scrolls games, since in Daggerfall, their physiques were also not much different from humans, in fact, the Khajiit are a step above Daggerfall since they actually look like anthropomorphic cats, instead of just elves with cat tails. It's still a step in the wrong direction, mind you, seeing as in sequels, I generally want things from older games improved upon, and if that's too much to ask for, I at least don't want to see any step backwards, but it's still not entirely fair to say that they were missing the point of the races.
Having games in the series where the various Kajiit or Argonians far outnumber the men and mer strikes me as being less "marketable"
As far as I'm concerned, players who wouldn't want such a game have no clue what fantasy is supposed to be about, and should be completely ignored by Bethesda, fantasy is, or at least, should be, about creating unique worlds that are different from our own, not showing us the same old, boring, cliche world of elves and knights and dragons, but since Todd Howard thinks that gamers want familiarity rather than creativity, I'm sure that Bethesda doesn't care what I have to say.