CM's have more money than you think they do. It's true that residents working part time barely make it, but people in the College Program spend about $400 a month on their rent, way down from what people not in the CP spend. They do have to share their room, but the point is, they have plenty of money.
I personally know people within the CP and they go to the parks at least two days a week, sometimes three or four, in addition to their 40 hour plus work week. Most people in the CP aren't paying student loans yet, they're not making car payments or supporting children, so they have plenty of cash. Full time employees not in the CP are less likely to visit the parks on a regular basis, in fact, I know some never do. Still, you're talking thousands and thousands of employees, the majority of which are very young and not so smart with money.
It is true the local people are most likely to go on weekends, simply because that's when most people are off from work and that's when their kids are off from school. However, most of these people will probably be keeping their kids away from the booths and Food and Wine. It's not that there are no 40-somethings getting drunk at Epcot, but that crowd is definitely ruled by people in their mid-ish 20's, many of which just happen to be the same age at the College Program.