It's simply not true and very observable if you've ever been at a company that does layoffs. Plenty of good teams get let go or entire groups in the company from management down are let go, it just doesn't make sense that they would all be "low-performers". Some low-performers will be caught up in layoffs, sure, but plenty will remain at the company too.
Might be conflating groups with individuals. The teams/orgs that tend to be hit the hardest tend to be not the most productive/cutting edge except when they're research teams way out on the horizon.
