i don't get why he still isn't on the powerplay

I'm with you, although Babcock likes to have a right-handed shot at the point on both PP units, but I agree that he should have gotten a more realistic shot on the PP when everyone was hurt.
I attribute most of his recent struggles on lack of confidence, which began when he went cold offensively. That and having Lebda as a defensive partner magnifies every little mistake he makes because neither of them are good enough to cover for the other when one decides to pinch in, and both of them like to.
I hope he can turn it around, because we have all seen the kind of upside he has, and he could develop into a top 4 blue-liner on this team for many years, but in the here and now it's been painful to see him (and the team as a whole) struggle this much.