The fact that the article features an English professor is unsurprising. This is a supply-side problem--liberal arts degrees are in relatively low demand, but institutions continue to graduate students at unsustainable levels. No one is telling the students that they're spending 4-12 years getting an education which is worth less than what they're paying for it. For the most part, the only jobs that hire for English…
https://en.wikipedia.org/wiki/Liberal_arts_education
Humanities students do indeed go on to earn less, but the differences are much more slight than stereotypes would have you think. They also narrow as people progress in their careers:
https://www.insidehighered.com/news/2015/10/05/new-data-what...
There are indeed too many PhDs minted in the humanities, but I'd say this also applies to pretty much every field other than, perhaps, CS. Times are pretty tight for bench and social sciences as well.