Of course, this is just one screengrab from one match, but it's true that healing in the BGs is just plain sad. And it's not surprising why-- there's a huge focus on DPS and taking the other side down in BGs, and there's almost no reward at all for healing. Out of the eight stats listed on that screen, only one of them has anything to do with healing (OK, bonus honor and HKs might get a nice boost if you're a good healer, but at this point, odds are they'd get an even better boost if you're DPS). Healers get all of the damage (since healers are targeted first), and none of the glory.
I'm not sure how we can fix this, either-- tracking "average lifespan," as a way of recognizing healers who stay alive? Providing bonus HKs, just for healing? Providing better PvP healing talents and gear? Personally, I love healing the BGs-- I love sitting behind a tree and keeping my faction alive long enough to take the flag or kill the other team. But right now, it's pretty much its own reward. When a Lock takes second place to a Priest in PvP, you know players need a little more incentive to break out the Greater Heals and Healing Waves.