I don't think there's any specific problem that forced it, mainly just because of the horrible lack of twinks actually queueing. In the few bgs I joined, I got perhaps 1-2 in total which had more than 2 twinks across both teams. 17k hp level 80s wanting to gear for leveling in wrathful wasn't quite so...inviting.
So I just bug my way into exp-on bgs now.