I've said before that I enjoy Alterac Valley. Even with my somewhat limited PvP abilities I've managed to rack up thousands upon thousands of HK's in there, ground up enough honor for the HW sword before the expansion came out, and have continue to play through the AFK'ers and into the dawn of this new, glorious age where AFK'ers get much less out of it. In all that time, I've listened to my fellow Alliance complain that they can't win in PvP and I've listened to my fellow Horde complain that they can't win in AV.
The two characters I primarily run AV on are my Tauren Warrior and my Night Elf Warrior. And both have probably won and lost AV about the same. People complain about choke points, about AFK'ers, about terrain and NPC's and Windsor only knows what else sometimes to the exclusion of playing. I can remember one AV where someone was so incensed about people spending their time in the cave that he actually went into the cave and counted them all while the Alliance was making their big push on Drek'Thar.
Quite honestly, I sometimes wonder if the factionalism of some players makes them blind to reality. If you're so invested in the Alliance and how it does in each BG that you don't even bother to play in the first place, you've actually managed to defeat yourself. One of the reasons I hate taking my NE warrior into Arathi Basin isn't because the Horde win all the time - in my experience whatever side I'm not on is usually a Tier 6 premade who stomp us like pacifists at a 'We love to kill people' rally - but because there's always that one guy (could be a woman, to be fair) who drank the I'm the best general in the universe and you must execute my order like the Ghost of Patton gave them to you Kool-Aid before signing up. I won't take my tauren in because I can't get through doors on him sometimes. (Hey, try running BRD on a tauren, it's a miserable experience.)
I understand that the game is based around faction animosity to a great extent, but behind all the trash talk and ego preening, the player base for each side really isn't at all different. Having played multiple 70's here, I can assure all of your Horde who cling to the idea that the Horde is more mature, you're living in a completely different fantasy world than Azeroth. And for you Alliance who sneer at the Horde as the goth kids wanting to play monsters to feel cool, it's simply not so. Are there individuals on each side who live up to those stereotypes? Sure. But having done raids, done PvP, leveled and quested as both Horde and Alliance, it's frightfully easy to forget you're even playing on the other side. People will always remain people.
The BG's aren't perfect, but in the time I've been playing them, I've never experienced a day where the Horde or the Alliance dominated them. Perhaps my battegroups are rare in that extent, but I do have to wonder how it's possible I can actually win on either of my toons at least 50% of the time if one faction has such a massive advantage over the other. How much of this can possibly be reality, and how much is just people going in believing the hype?