Indeed. While one should always look to check on other biases in play, in my experience "F" players survive layoffs almost as often as "A" players, and it's those in the middle that get hit. (Sometimes this may be because the "F" players aren't getting paid as much, and are therefore cheap.)
Not to mention that the remaining "A" players may each be saddled with the work of ten laid-off "C" players because, as far as management is concerned, programmers are fungible. Why not have their 10x programmer take care of it?