I think it's useful for society to have a significant chunk of the population that knows a lot about social sciences or humanities, even if it doesn't translate directly to job skills. On a simple level, as a trans person, I would be really glad to know that my office manager majored in gender studies. On a more grand level, I think it would be good for US foreign policy if every voter had at least one friend who had studied international relations. Therefore, I don't see it as a social problem that we have a lot of people spending a few years of their lives studying those things, although I do think it's a problem that we charge them absurd amount to do it. By contrast, I don't think that whatever they teach in "online marketing" has any positive effect on society. It might even be negative. Those degrees I do see as a social problem.

I also agree that it's a problem that a lot of people are going into college just because they don't have any other ideas and it's seen as a respectable thing to do. I think the main cause is that our society doesn't give nearly enough support to people entering the workforce, and is oddly determined for people to move from being a full-time student to a full-time worker, with nothing in between.