I care about preformance, but i wont sacrifice having to look at an ugly character for over 2 years for that tiny bit of dps.Which is a larger gain than almost any enchant... yet guilds require you to be fully enchanted and no one complains. It's just 300 DPS, right?
It just depends how much performance means to you. Is it really important? Then race should be important too. If it not really important? Then play whatever you want, who cares. Lots of people care about performance so they pick an optimal race. Whether it really matters or not depends on your perspective. If you mean does it really matter for doing the best DPS you can do? Absolutely. It has nothing to do with playing perfectly. Going Orc gives you what amounts to a free 1% DPS as SV/Marks and a free 2% DPS as BM. That's without changing anything. If you use Blood Fury it's higher. Same goes for Troll. If you suck you can bind Berserking to some shot and go about your merry way and see a DPS increase. If you're smart about cooldown stacking you'll get much more out of it.
The only thing that matters is how much you care about performance. People arguing that race doesn't matter don't care about performance. It doesn't matter how much they claim they do, or claim the differences are small. Racial choice is more important than regemming a new piece of gear, or enchanting it. (Note: Monetary concerns are another issue entirely. RL should always come first.)