Some people claim that trying to balance low level pvp is a waste of time. Considering how much time you spend leveling a character, especially if you're new to the game, I don't think it would be a waste of time at all. Cataclysm was very much targeted towards newer players, and retaining their subscription. I'm sure the absolute lack of attention towards balancing anything below level 85 has influenced people to unsubscribe.
Imagine being a new player to WoW, and having a lot of fun playing the game. All of a sudden, you get level ten and try out a new thing called 'battlegrounds'. You're excited to try it out, and see another player on the opposing faction with some heirloom gear. You try to attack him, and he kills you as soon as you get anywhere near him.
Afterwards, you decide to try to hang with your team. You're going for the flag in warsong gulch, and you're one shot by a rogue who you couldn't see. You try to figure out why you're dying so quickly, only to find out that it's because you don't have a max level character able to obtain heirlooms.
If any player tries to describe his experiences in lower level pvp, he's immediately hit with "pvp isn't balanced until level 85, get over it". Getting to max level is a pretty daunting task for a newer player. Do you remember the first time you hit the level cap? For me and most of my friends, it seemed to take an eternity.
Lower level pvp doesn't need to be absolutely perfectly balanced. All I ask it the blizzard at least tries, for their sake and for the players sake.