Ok there is an economic theory about this:
Public goods get abused. You make available something free, someone, or some group will ruin it for everyone. Make it somewhat cost prohibitive (charge a small monthly fee), you will scare off the brokedicks and stupid assholes.
Example: If you charged a fee at public parks, you'd probably deter "certain people" from getting there, taking all the public grills at 9am and making a horrible ruckus the rest of the day.