Of course layoffs naturally include low performers, but they also include employees across the board. The highest weighted metric is usually compensation relative to what's perceived as the "market" rate, which is also a sliding scale and open to interpretation.

This idea that these types of layoffs are simply "trimming the fat" just doesn't jibe with my first-hand experience, nor the second-hand experience learned through other employees. I've seen some of the best performers get axed while the sycophants and low performers get to stick around.