A lot of older fans wear them these days because when they were younger they were risking a kicking if they wore them to games . It for the most part is the complete reverse these days .
I had a replica shirt in the seventies . I would not dream of wearing it to games .Way to dangerous.
I went to see Starsky and Hutch in the cinema and wore a 'Starsky' jumper that I had had since the seventies. Did it for a laugh more than anything else.
But this is horses for course . Recently went to the Sonisphere festival . 90% of the people there wore a t shirt supporting their favourite...