My first reaction was: Doesn't everyone, at least when it comes to “genre appropriate”? But then I remembered the Arduin Techno character class. The real limitations I'd impose along with genre are “able to get along with all the others” and “plausibly sane” which are both fairly vague; and usually unspoken or implicitly expected of players. I have done “no non-humans” as an explicit limitation in D&D games, but that has been a part of the setting — I've deleted the damned clichés and added in different races without the usual baggage of preconceptions.
I don't really recall any significant player reaction; the general principles are part of the cooperative playing style that evolved fairly naturally; a style that led to “Does not compute!” reactions when later once faced with Paranoia.
There are a couple of instances where I should have limited but didn't — vetting character secret agendas up-front for the Vampire game (rather than having it explode into five separate solo stories), or helping a player doing a one-off appearance in out mid-80s Champions game who had no experience of the superhero genre to build a superhero rather than a fantasy character.