You know how this works. Maintenance development is handed to junior developers allegedly overseen by a senior developer, but the senior dev is busy on other projects (e.g. BF3) so he never has time to help the junior devs out so their code never passes QA and thus gets delayed repeatedly. Hence being so late.
There's no real money in late patches, when viewed over the short arc of a few months or a year, so they're not going to put their experienced guys on it. From a certain point of view, one might say there's no money in patches at all. That seems to be Creative Assembly's position, as they refuse to fix / deny the existence of the underlying save corruption problems that have plagued them for the last three games, and people buy their games anyway.