I disagree.
There must be an element of toughness in this game. Players that aren't strong minded enough to get in when the going gets tough, is rightly looked down upon on the field.
When you go and play footy, are you expected to go in hard? Yes. If you shirk a contest, will a player let you know about it? Probably.
If we were to go by your logic that "If I can't do it, I can't comment", then wtf none of us should be commenting on games except for "I applaud him, he might have shanked it out of bounds, but I never would have taken that mark in the first place".
When you play at AFL level, you are expected to play at AFL level, no matter whether the criticism is coming from an ex-AFL legend or a guy who barely runs anymore.