To be fair - I can certainly see why you are annoyed by this, but I don't think it s realistic to ask for a bug free version of GC3 vanilla *before* any more DLC etc is done.
Because that would require complete knowledge of all existing bugs to happen. But thing is that bugs are not all discovered instantly, some may still lurk around if they get triggered in certain situations only, and some may also be the result of patching.
So IMO the best we can do is to report bugs, and the best SD can do is to fix them on the way, but it should not stop them for working on further releases. Also, I don't think working on those further releases prevents them from fixing older bugs.