You actually post well about the game. I agree that you don't necessarily have to have played to be able to understand it. Having played can help and coaching broadens ones appreciation but I'm guessing that most of those who post on BF would have played at a level where the tactics would have amounted to not much more than "kick it up the guts" or "handball to a mate running past".I haven't played football. But I love watching it and consider myself to have at least an adequate knowledge of the game. To claim that you have to have played it to have an opinion on it is as ridiculous as saying you have to have been in politics to have an opinion on an election.
This is especially apparent when one reads the rubbish that a fair number of Crow trolls here put out. One can only conclude their only contact with a footy was during kick to kick during lunch break at their school. Even then they probably relied on "waxing" with a friend who could actually take a mark.