Depends on the class, if its a warrior or rogue has to be female...usually the smallest (non dwarf or hobbit) race there is
Cleric can be either, casters are male as are shammys or druids
Just always the way Ive played...Now
as far as people saying they have a problem with others playing female to get "fat loots" how pathetic must you be to try and coax a pixelated toon into (im guessing here) cybers for loots...I mean come on, play the damn game and quit trying to score. Its not a freaking dating site.
If I have a female RP character than I will RP as female, but with that being said I have never "hooked up" with someone in game...if a dude was getting a little to chummy I would just send them a tell saying 'sorry but my character isnt looking for any involvement" and if they kept on then they were put on ignore...easy peasy lemon squeezy.
Its my game, I will play the way I want and if you dont like it...well you know where you can kiss it
I have fun playing as either gender though I tend to do female ones more often. In primarily third-person games a factor is simply what I'd prefer to look at while running around for hundreds of hours. Any number of things will influence my decision though. And sometimes I just find it incredibly fun to do something like run around as a pretty lady who makes a habit of smashing things with two-handed weapons.
I have no issue with people playing as a different gender, whatever their reason. Even if it's to try and get extra handouts or something...a fool and his money. *shrug*