I am with you on the fact: I don't like to wear jerseys in public. I think it's kind of lame. I'm not the guy who is out doing his groceries in a jersey or at a bar in a jersey...
But I do have tradition of putting on a home or away jersey (depending on match) when I watch the game.
Plus it's a nice collectors item. Becomes cooler when there are new sponsors new designs and yours becomes vintage...
I used to wear my jerseys everywhere. Family occasions, going to the mall, hang-out with friends etc. But nowadays the frequency had been reduced, simply because I (like every young husband-wife couple do) share the duty of carrying my son with my wife. And whenever you have a 1-3 years old son in your arms, the hazardous chance of your shirt getting wet (drooling, puking, burping) is increasing.
So now my jerseys are mostly wore before watching Milan games on TV, very seldom wore out of the home, even if I wear it out, I always ensure that the place is air-conditioned to reduce the chance of sweat tarnishing it. And before they're back in the box, I always hang it inside out minimal 24 hours in a shaded open air area to get some 'fresh-air' and to remove some of the folding marks.
Another thing, I prepared something like a stock card listing the day when each shirt is wore to ensure proper rotation and to avoid certain shirts getting over-worn. So before every game, there's a 5-minute ritual of checking the excel file in my laptop and decide which jersey is going to get the honor