Dudes have always mocked other guys who wear jersey's. It's a generalization of course but on most any sports board you'll see it done.
I mean ultimately it's to each his own and I sure as hell wouldn't mock some ripped 300 pound guy wearing a jersey to his face but in the big picture wearing a jersey isn't always considered masculine for adults to do. (kids are a different story)
At the last game I attended there was one of these big ripped hulks wearing a Steelers jersey... over his black and yellow kilt.
If you're at a Steeler game you'd stand out by not showing the colors.



