So why do people hate the various races of elves (Elves, Eladrin, Drow etc).
Because there are hundreds of elven subraces but dozens (or less) for orcs, gnomes, dwarves, etc. And many subraces (elven or not) are just mind-numbingly stupid. (There are more elven subraces, so more stupid subraces, and more subraces that any individual won't like.)
Subraces add complexity to a game that doesn't need them.
In 3.x (and, I suspect, after a few years of 4e) subraces will just exist as a form of cheese. Anyone remember the "wild elf"? (Be an elf with no Con penalty!)
Wild elves are a cultural group. They might tend to have higher Con scores and lower Int scores than most other elves, but then uncivilized humans may experience the same thing without needing an actual subrace to describe them. (Similarly, elves who wear togas and live in crystal spires might tend to be more intelligent and more frail than other elves; humans or dwarves who live in such scholar cities wouldn't get a subrace, but such elves would be called moon elves, gray elves, sun elves, or whatever.)
The elfitis problem even extended to lycanthropes. Elven werewolves (lythari) had different alignments than other werewolves and were a distinct culture (for no good reason), even though they used the expected stats and thus were not mechanically jumbling or broken. Why do they exist? Because an author who liked elves wanted to create their own elven culture (instead of just creating their own town or something). Sheesh.
Honestly, I would dump eladrin except they have cool racial abilities (and it's too complicated to actually ditch them, unfortunately). So in my campaign, there will only be elves, eladrin and drow. No aquatic elves, and any winged elves would be a "mutation" that could be found in other species.
Does Tolkien have anything to do with it?
Not really. He made elves "better than thou" but that's not a big part of the elfitis problem*. Tolkien's Middle Earth only had Noldor and Sindar (the Vanyar never returned to Middle Earth), which are the equivalent of eladrin and elves, respectively. Tolkien had no drow, although there was a single pale-skinned evil elf called "the dark elf".
Elves like Legolas were down to Earth (a big deal, considering he was an elven prince).
*It's part of
another problem.
And why oh why don't you change them until you like them again?
By eliminating most subraces? I believe plenty of DMs have done just that.
Think of it this way. Someone doesn't like strawberry ice cream, and wants to buy a dozen buckets of ice cream. Which makes more sense, changing the strawberry recipe until they like it (at which point it isn't strawberry anymore), or just buying a dozen flavors they actually like?