Please spare a thought for the QA testers.
I was in commercial IT for 40 years before I retired. I started on mainframes, then mini-computers, through the rise of the PC and left as web applications became the norm. I’ve done my share of testing.
Delivering to PC was always a nightmare. Even in-house, where we tried to control the PC build, they always managed to be inconsistent. As much as we tried to have a variety of testbeds, we knew that someone would have problems.
I cannot imagine testing a game as big and open as BL3. It’s impossible to define everything that can happen and, therefore, it’s impossible to test everything. Thankfully, I’ve never had to test a game but here are just a few of the things I can see that need to be considered - character movement, vehicle movement, skill combinations , map consistency and integrity, NPC actions and dialogue, enemy AI, specific boss AI and a system that can procedurally generate over a billion guns! I’m quite sure there are a LOT more. Think how much the QA team have got right against all the odds.
As for the technical issues, I’m sure GBX have a good range of test PCs but those numbers are trivial compared to the hundreds of thousands of machines that are running the game. As I’ve said, no two user PCs will be the same. In topics here, on technical problems, I have seen people with PC specs identical to mine having all sorts of problems, yet I am playing glitch free.
Posts above have noted how buggy modern games are. If we want the large, complex, open world games we have come to love, we must also expect some problems. The fact is, any large, modern "AAA"game is untestable, if you want zero defects on release. If you want to play on Day 1, you will find problems. If that annoys you, wait a few months for patches to drop. That we have a functioning game at all is thanks to the work of the QA team.