Lots of lower middle class families have been deep in debt at some point. They know how tough it can be trying to pay off debt, especially with an entry level job right out of college. Since they know how tough that is, they want to sacrifice for their children to give them the best possible chance at living a good life. That's why some people struggle to put their kids through college even though there's "free money" available. It's not hard to understand, because "free" loans aren't free, even if the college graduate does have a decent chance at being able to pay them off over the next decade.

I'm not saying that parents that let their kids take the loans are bad parents, but it shouldn't be hard to see why some parents don't want their kid to be saddled with debt upon graduation.