One of the biggest emotional triggers is unfairness. You can see this in anything with a brain from small animals, children through to adults. If there's perceived unfairness emotions are immediately and strongly triggered.

Layoffs are truly unfair. You have no control over them and no performance or ratings process is good enough to justify snap firings of some percentage. You're going to hit some of your hardest workers.

Honestly i don't think it's the self-worth or anything like that that gets to you. It's the sheer unfairness of the situation. I also think simply realizing this is helpful.