It doesn't necessarily work that way, though. If tests tell you you broke something immediately, you don't have time to forget how anything works, so identifying the problem and fixing it is much faster. For the kind of minor bug that's potentially acceptable to launch a game with, if it's something tests detect, it's probably easier to fix than it is to determine whether it's viable to just ignore it. If it's something tests don't detect, it's just as easy to ignore whether it's because there are no tests or because despite there being tests, none of them cover this situation.

The games industry is rife with managers doing things that mean developers have a worse time and have the opposite effect to their stated goals. A good example is crunch. It obviously helps to do extra hours right before a launch when there's the promise of a holiday after the launch to recuperate, but it's now common for games studios to be in crunch for months and years at a time, despite the evidence being that after a couple of weeks, everyone's so tired from crunch that they're less productive than if they worked normal hours.

Games are complicated, and building something complicated in a mad rush because of an imposed deadline is less effective than taking the time to think things through, and typically ends up failing or taking longer anyway.