Because we're better/smarter/faster/stronger than them and therefore make the best decisions all the time in any scenario and therefore can criticize anything they do.
Welcome to the internet.
@Albany,n.y., I'm sure players opted out for different reasons, but some may legitimately not want to risk catching covid.
You seem to be implying that because the NFL is doing a great job of monitoring it, then the players won't catch it or be affected...