Whereas the Tolkien races make me cranky*, so what are you gonna do?
I mentioned that in the second or third sentence. You know, the one almost no one reads
By the way, I wasn't even born in 1974. I thought Tolkien's books were older than that though.
[SIZE=-2]*Seriously, they do. Come on, guys, it's not 1974 any more. Fantasy fiction moved past slavish imitation of J.R.R. Tolkien a long time ago. Why do we have to have these tired old retreads pushed on us in every PHB and jammed into every published setting? I know it's futile to complain, the elf/dwarf/halfling trio is the sacredest of cows and will never be touched, but a man can dream.[/SIZE]
Probably because they have crowded out most other races. Take a look at the gnome. It took 3 and a half editions to have an actual identity, as before it was just a cross between dwarf, halfling, and elf, the exact mix depending on the setting. (Eberron, Golarion and 4e all made good use of the gnome, but gnomes prior to that were seen as jokes, literally in the case of Dragonlance.)
And then there's the "planet of hats", where the race might have a personality, but it's exactly the same. Kender fit this trope pretty well. Except for the afflicted kender, they all have identical personalities. GIthzerai are all psychic monks. Githyanki are all war-obsessed pirates. To an extent, dwarves suffer from this, but less than most of the less popular races.
There's races that cause RP problems. Drow and kender fall into this camp (for very different reasons). Even thri-kreen; I like them, but they're far better as NPCs than PCs.
And then there's races that can't be taken seriously. Kender
again, but also gully dwarves, some gnomes, catfolk... admittedly this is a matter of taste (there's no official catfolk that I'm aware of, so they don't
have to be goofy).
There's cheesy races. Drow in 2e, goliaths in 3rd Edition, pixies in 4e... Pixies also fall into the whole "hard to take seriously" area.
Even looking too different (tieflings, dragonborn) can run into this problem. Unless you have a setting where weird-looking fiend-bloods are tolerated, tieflings don't really fit in. Planescape is a great example of a setting where they
do fit in. Isn't that the setting that introduced them?