No offense, but I think you are looking at "culture" through a pretty narrow lens (or just not talking about "culture" at all)...
Regardless of if you are "[hiring] way too fast" or "finally [getting] rid of subpar performers," layoffs are still, by definition, firing a bunch of people's coworkers. Simple work efficiency, which is what you'd theoretically be improving in both of your examples, has relatively little to do with company culture, so your examples aren't very compelling evidence.
Regardless of if you are "[hiring] way too fast" or "finally [getting] rid of subpar performers," layoffs are still, by definition, firing a bunch of people's coworkers. Simple work efficiency, which is what you'd theoretically be improving in both of your examples, has relatively little to do with company culture, so your examples aren't very compelling evidence.