Funny, I distinctively remember contributing to a huge number of Horde vs. Alliance threads. Silly me, must be my brain malfunctioning what with me playing Horde and all.
Trust me, the grass ain't any greener on your side. Also, is it really worth getting worked up about something like that? Let others call your faction kids or morons or whatever. I trust you're a decent person, but replying to someone like that by flaming them makes you lower yourself to their level.