Ultimately the blame goes to UBISoft for releasing a game in such a terrible state, if the developers said that it was ready then the developers are to blame!
However, what I think is that the developers are under such a strain of pressure from the producers (higher up) that they give the go ahead knowing it's not ready but don't really have a choice in the matter, it must get frustrating when they are told to "wrap it up" for release!!
Even the patches can only go so far, and like any workers they're not going to work for nothing!!
Well that's just a guess but probably not far from the truth, IMO!
PS. And the type of DRM is totally the produces decision!