My biggest concern over all this is that the policy change came so quickly after the SA thread (similar timeframe as the Anderson Cooper clip). Even though startups and usually praised for moving quickly, I agree complete with the OP that this can be a major directional change (positive or negative) for Reddit overall. This kind of stuff should be thought over long and hard, rather than come down from their parent company. Reactionary policies that sprouts from avoiding bad PR will be good for the short term, I just hope they thought it all out what they will do in the long term.
Not that I'd like to defend this move, but it probably has been on the table for a long time now. /r/jailbait was banned and reinstated enough times for the discussions to have gotten old in reddit HQ by now.
my interpretation- they were WAITING for an outside party to speak up about it, so they could say "well, x party forced our hand" to shift the blame. Reddit (the company) is terrified of upsetting its userbase, lest it go the way of Digg.