Because it would be much more efficient to have people who know what they are doing do it. Though I'd love to see the potholes in my city fixed up, it would be quite insane to start learning how to patch the roads myself and then pestering the DPW staff who didn't ask for my help for access to their equipment. In addition, I have no idea if the people who run this site have any motivation to improve it. Maybe they are perfectly happy with it precisely because it chases off the unserious. Or maybe they would love to improve it but need time/money to make it happen. Maybe the last time they tried it was too much headache. Maybe the key guy who did all the original work died. I simply have no idea. I'm just wondering why the site hasn't changed in 16 years.