What's wrong with being proud of the team you support? The only reason we don't see it as much over here is because it rains so bloody much and visitors don't get the chance.
Or would you rather see middle aged men with their pale white beer gutts hanging out and man boobs in view for all to see??!!!
My point is that any time I go abroad you always see some nyaff in an old firm top which disgusts me so this has caused a knee jerk reaction in me when I see any football top at airports or resorts. This is only when adults are wearing them of course, kids are okay.
Also wearing a football top doesn't prevent the beergut hanging out. It's varying degrees of decency I suppose but it's my opinion, I'm not expecting anyone else to adopt it.