I don't get irate with people who don't sign up either. It's everyone's choice, and not everyone should have to buy the right to support/follow/barrack for a footy side if they don't want to. The whole appeal about footy is that it's a relatively cheap passtime (though these days it's not that cheap) and it's easy to get passionate about. I absolutely despise the attitude of many around here that if you're not a member you're not a supporter. It's pure rubbish.
Having said that, I do believe that if you are not a member then you forgo the right to have your voice heard by the club. I'm sure that by courtesy they will listen to any supporter, member or not, but they're not obliged to. If you're not doing anything for the club, then it's unreasonable to expect them to do anything for you.