Plenty of A players might be assigned to pointless projects which could be axed wholesale.
These companies could take a more twitter like "print out your code" or global stack ranking to lay people off but i don't think it dodge the problem people describe. The "A Player" could still be mad that all their coworkers got fired and/or the "pointless project" they enjoyed working on got axed and still leave. You just get the add cost, drama, and blow-back (see twitter) that a performance based firing would entail and probably open yourself up to lawsuits (IANAL) if you don't have an adequate paper trail for those performance based filings.