Why does the Horde suck so badly in Battlegrounds?

I play on Altar of Storm (NIghtfall Battlegroup) and we can't seem to win any battlegrounds. Over the past week, I've played around 50 and won 8 of them. It seems as if only a few people can actually do anything helpful. Why does the Horde suck so badly on the Nightfall battlegroup? And is there anyway they could stop sucking?