Such absolute rubbish, i'm sorry. This ridiculous theory that all alliance players are 12 years old and all Horde players are married with kids is really stretched thin.
I don't recall playing to that stereotype, though I've no doubt there is a slightly different demographic between people who choose the 'pretty/identifiable' races (of which alliance has more) and the Horde, whose appearance is more 'evil/unidentifiable'. Call it rubbish as much as you want, but Horde win more battlegrounds than Alliance do - the only exception to this has been AV which (until the recent changes which have pulled it closer to 50:50) Horde used to be able to play all day without a win, owing to blatant map imbalance. I have a Horde Priest and an Alliance Mage, both of whom go to BGs regularly, so it's not like I haven't seen both sides of the argument. A win outside of AV is a treat for my Mage, but my Priest goes into every BG expecting to win.