Well, economic benefit shouldn't necessarily be the sole factor in determining whether a subject is available. In the end it's not like you can determine how much a subject will be worth in the long run.... And if my sources are right, even liberal arts students don't do that poorly in the long run career wise. They start of slower than technical careers but over the long run they even get higher incomes... And to boot,
quite a few CEOs are liberal arts majors, some sources even suggest a third of CEOs have such majors but I haven't found one I am comfortable with (t
his one suggests less but still a few). Surely the US has education issues but I wouldn't necessarily say it is too many useless degrees or subjects. I would say the issue is on access and quality (for people not going to top schools at least) rather than specifically a degree being useless. In the end life is long and complicated and not necessarily reduced to merely whether you have a science degree or not (though I do personally favor technical degrees over liberal arts).
on another note,I also found this to be an interesting read:
http://www.politifact.com/wisconsin/article/2016/mar/27/final-five-truth-o-meter/