People get passed over for jobs they are qualified for just because hr departments throw out all the applicants who don't have a degree, even in an unrelated field. It makes it so that these people do essentially 'have to' go to college to get jobs, even though they'll get all the training they need on the job.
Aside from a manufacturing or manual labor type of job I don't know what job you are thinking of that you would get "all the training they need on the job". I can think of a lot of fields that I wouldn't want a DIY or on-the-job trained person to be working in - structural engineer, dentist, surgeon, even lawyer.
In our field (EE chip design) we don't hire people that need on-the-job training - the people we hire will eventually end up as our coworkers, not our trainees. When we interview people we always look for degrees (generally MS or better, but occasionally BS). If someone doesn't know the field (coming from an unrelated background), and can't even show a BS degree, then they aren't going to cut it as a coworker because they won't know what the hell they are doing.
A degree is more than a rubber stamped piece of paper, it shows an ability to apply yourself to a given task for a length of time and actually accomplish that task. It's a pretty low bar really, especially for a BS degree, since the whole education is guided and taught to you by someone else (advanced degrees generally involve a thesis, which shows some ability to guide oneself and accomplish a project).
Personally (as a person working on a PhD in science) I don't think a lot of people need to be going to college. I grew up in a car town, and a lot of my friends knew they were going to be doing manufacturing, but they went to college anyway.
This I don't get, unless they got useless degrees, or are simply incapable of moving to a place with better job opportunities. The town I grew up in didn't even have a college, and I was always dismayed at the absolute apathy and disinterest in the people there to improve their lives. Finally getting to a university I found to be a refreshing experience, as most people there are motivated to do something better with their lives (as contrasted with say the aforementioned town's high school where most people couldn't wait to leave and get back to their minimum wage jobs, apparently oblivious to the fact that their career path would go absolutely nowhere).
It also occurs to me the people who wrote TFA need to hook up with business leaders who claim that they need more H1Bs because there are not enough qualified applicants from here in the US.