PVP balancing, in my mind, revolves around three things. Survivability, CC, and damage dealt. Quick definition - by survivability, I mean both damage taken and healing capability rolled into one. IE, one might say a healer and a tank spec both have high survivability, and they do, but in different ways. Same concept for the point I'm trying to make.
Ret right now is only decent - not good, decent - at one of those things. We can burst once in a while in ways that some people consider to be 'good' but even that is miles behind what other classes are capable of. Our healing, self and otherwise, is crap, as is our laughable damage mitigation. Add to that a pretty pathetic CC roster (especially for a dps spec) and you get real close to free HK territory.
Compare that to say, a mage. They have an amazing array of CC options, a personal shield that was very very OP until they nerfed it down to great, and their burst dps is every bit as good if not better, only they get to use theirs a lot more due to being ranged and having so many CC options. The only small advantage ret has over frost mage is that we can kind of heal other players, but that is so insignificant to the damage and CC disparity that it goes unnoticed. I use mages as an example because of personal bias - I hate the little shits - but there are several other classes/specs that you can make the same comparison to and will end up with the same results.
So to bring ret back to something decent, one of the other two needs to come up. Either our ability to CC or our ability to survive and help our allies survive. Or the alternative, bring other classes down.
Ret is not the only spec that is in this situation, but it seems like Blizzard doesn't give a crap that we are here. I haven't started really watching the 5.2 changes and I don't play PTR, hopefully we'll get some love but it's been a long time since ret has been anything more than an off healer spec that few if any groups want for any kind of PVP. Cata relegated Paladin PVP options to spec Holy or run a BG flag. Then MoP came and now it's just spec Holy.