Because it gives them a piece of paper that some people care about. That is, compared to learning more but not having the paper, it improves the odds on them being hired.

How do we fix that? We need somebody to become credentialed (or some institution that already is credentialed) as an institution of higher learning, that will curate a list of online classes (not necessarily their own), provide some way of grading those classes (online testing), and issue a diploma that is recognized by the offline world.