In my opinion, most of this is almost always selective perception. For example, all those guys claiming that "alliance sucks" and they "always lose in BGs" should check their statistics. Most of the times, they have played at least 50/50 in the BGs. But they only remember the BGs they lose. I mean, there are people complaining that alliance totally sucks while WINNING a BG (Don´t know, probably the same type of people is on horde too). They literally say that all are stupid every time you don´t win insanely high. If you win by less than 500 points in EoS/AB, alliance sucks. If you don`t win by rush in AV, alliance sucks. It´s just...idiotic.

As to WG, well, WG is kind of like a population meter. The side with more people on it will control it more.