Don't get it, either. But it's happening all the time.
I've been involved in several betatests over the last decades - and releasing unfinished products seems to have become something pretty common when the product was software driven and could be updated (it's even worse with pure software products).
At least rather often, once a product gets closer to release, testers are being asked whether there's showstoppers left, both obvious and hidden ones. At that point in time there shouldn't be any obvious ones anymore, yet, some will often still slip through. But there shouldn't be any hidden ones anymore, either (the TBP ones might qualify as such). And those are actively allowed to slip through all the time, at least given my experiences as a tester and a user.
There's some reasons why this could happen, corporate greed (as the-trooper already mentioned) certainly being a major one. But sometimes companies just have less than qualified betatesters, such as folks being way up the arse of the company because they feel so special being testers (betatesting fanbois are the worst that could happen to you as a company, but for obvious reasons companies still love them), such as folks not really having a clue (often true for celebrity testers), such as badly coordinated tests and what not. I've seen all of this happening more than once (and sometimes all of it together). It's really making you wonder, because in the end it's absolutely stupid - but it still seems to happen again and again.