I'd be fairly confident that when posters say "Ah the good old days..." they are tongue in cheek referring to their advancing age and the eras of football they've seen rather than condoning or glorifying violence on the field.
Of course the Cronin family would be upset by any violence given their son/sibling died from a coward's punch, no one is denying that. Using them in an emotive rant is tasteless.
I don't think Rance is a "weak dog" as you put it. I certainly see the irony in faceless people behind a keyboard calling him that, especially after he fronted the media, apologised and took full blame. What he did was stupid, out of character and could have had far worse consequences. Thankfully it didn't. There are no excuses for violence, people make mistakes, sometimes bad ones, nobody is perfect, he has been penalised by the AFL and we move on.
I do not like what Rance did one bit and it sends a poor message to kids about actions on the footy field. He has made significant effort to apologise and condemn violence, which will make some difference and should be accepted in good faith. Would the Cronin family be please to hear of Rance's public contrition?