The amount raised by fines is a pittance compared to the costs of police and fire protection for a town which has a college. Yes, the college has a security force or campus police.
But every frat party where someone pulls a false alarm (virtually every weekend night- starting on Thursdays and running through early Monday morning) or drunk kid who climbs out on a roof and needs to be rescued, or kids who try to ice skate on a partially frozen pond… these are actual costs incurred by the towns first responders.
I’d say a few hundred parking tickets barely puts a dent in the expenses a municipality faces trying to keep the “citizens” of a tax exempt property safe.