In the end, most players treat different races as some kind of costume, anyway, thus it isn't a big loss.
This. If the race is, basically, rural humans with pointy ears or short, grumpy humans or some such, there's no point. IME, this is the way most people play most races.
Right now, I'm running an Eberron game with an eladrin, a dragonborn, a warforged, and two halflings. One of the halflings plays up the race and the dragonborn uses her breath weapon every combat. I play up the warforged bit, but the player continues to walk into taverns and expects a normal reaction. Otherwise, there's absolutely no real reflection of the races in how they're played.
Personally, I don't think you
need non-human races in fantasy. Don't get me wrong... I prefer them to exist and even be PC options. But, I'm very much a fan of Gygax's humanocentric flavor. This is probably best represented in the "guideline" I enacted for my previous campaign: There must be more human PCs than non-human PCs (i.e. 50% or more) and no more than one of any non-human race. Of course, I also did my work and delved into what it meant to be an elf, the race's origins, traditions, etc. and how those would have impacted an elf growing up. I didn't force the player to adhere to a "stock" elf, but I was fairly clear about when she was acting against her upbringing. Lots of fun was had in exploring those ideas, too.
You don't
have to do a lot of racial navel-gazing, and I wouldn't expect it to be a constant theme -- I'm not pointing at bad-wrong-fun. But, I do think races should be something other than stat bonuses and an encounter power.