Bugs are often specific to platforms, so the bugs on the PC version don't necessarily show up on consoles and vice-versa.
Also, please be careful throwing around the word "broken". "Broken" means that the game doesn't work. It doesn't mean that there are sometimes issues with graphical stutters or stuck NPCs. To be honest, I never experienced enough bugs in Morrowind or Oblivion on PC to ever mod them out.
Good points. To the OP, bugs are something that at the end of the day are tricky and situational. What one personal may face on their PC/console another might not but might face some entirely different bug. And every game always has bugs.
Broken and Bugs are different things. But at some point your company can't give the time or resources to make a patch even if well known bugs still exist and have to move on.
For this I referr you to Obsidian Entertainment.
Despite Fallout: New Vegas being the most buggiest and most people affecting(in terms of bugs) Fallout game ever and the mass of bugs still left Obsidian doesn't want to make a patch.
Why? For those exact reasons.
I'm not saying these decisions to leave a product buggy or broken(Other than at release Daggerfall none of BGS's games have been particularly broken at all or mass buggy. I have faced bugs and some freezes here and there.) is fully justified.
I'm just telling you how it is OP and others.