Why don’t access centers just produce all the programs?

Most independent or municipal access centers are funded by a small cable license fee (usually from 1 to 5% of the local cable company’s revenues) which pays for facility upkeep, utilities, and a small part-time or full-time staff – usually 1 to 3 people, although some urban centers have several more. 

And it is these employees’ job to manage the public resources, train people in TV production skills, and facilitate the telecast of programs on the local channels. It is neither possible nor appropriate for them to be in the TV production business, for access TV is “Do It Yourself” TV.