In the real world that's a completely wrong way to look at the purpose of life and education, but in the small minded narrow constraints of the article its actually "correct".
A side issue is outside bubble areas, every low paid service industry worker has a liberal arts degree and they guarantee the ROI of self taught foreign languages or liberal arts will be zero. A guy looking for employment who merely is a lifelong expert on Japanese will never get hired if the competition is ten baristas, bartenders, and real estate agents all with bachelors or masters or PHDs in Japanese Literature.
However, to argue that a young person of modest means should study the humanities is just cruel. If your family and connections aren't going to set you up as a company vice president or send you to the legislature, your job prospects are dismal.
Also, I think people are fundamentally missing the comparitive here. My claim is not that learning humanities is "easy". Nothing worth doing is easy. My contention is that it is easier to learn math, engineering, and science in school and study humanities on your own that to learn humanities in school and then try to break into math, engineering, and science on your own.
And as I watch the conversation flow here, bear in mind I do mean "math, engineering, and science" here and not just "programming". Which is easier to do on your own, learn Japanese from scratch enough to get a relevant job, or learn biochemistry from scratch enough to get a relevant job? (Note we're also discussing "learning Japanese" as an extreme in the humanities but I consider "biochemistry" an average sort of what I'm talking about.) And part of my "easier" also encompasses the fact that life is a lot easier when you have a job and a paycheck. Someone who actually has leisure time due to not working two-and-a-half jobs and who is much more relaxed about paying off their loans will find it easier to spend their leisure time learning things.