That's a big assumption. After all, JRRT isn't the only one who wrote about elves. And how he wrote about elves changed over time ( http://en.wikipedia.org/wiki/Elf_(Middle-earth) ). Heck, JRRT isn't the only source used by D&D's designers that talks about elves.
And some of us players have also wandered far from JRRT's works as well...including sampling the very works that inspired him.
At the large scale, sure, there's still a wide variety of inspirations, but there are a lot of commonalities as well, otherwise the race wouldn't be recognizable as an "elf". Wouldn't those differences in interpretations make it more likely for a person to think "huh... that's not right..."? At least, initially? Sure, more mature players are likely to just let it slide and not have any long term issues with it, but I think it'd twig on the "not how I see elves" meter.
That's sort of my point though... why doesn't "wrong" portrayal of race wig some people the same way gender wigs them?