In other words, "the work I want to do is real but the work you want to do is trivial and pointless."
I really genuinely have enjoyed Paul Graham's writing over the years but moments like this seem arrogant and tend to spoil some of the enjoyment. I'd be genuinely curious to know what departments he finds pointless, and why, in the grand scheme of things, they have no "point" in comparison to computer science or whatever.
While it's true that computer science can be used to enable, for example, much cheaper air travel, or important forms of cancer diagnosis, it's also true that a great many computer scientists work on less crucial problems like optimizing ad targeting or enabling scams.
Similarly, while many English lit majors may end up contributing little most of us find valuable in that field, there are some who will become authors who genuinely help other humans find more meaning in life and feel less alone, and others who will shed new light on history and thiis contribute to the understanding of our present.
I'm not saying fields can't be compared. Maybe the average engineer's college studies help society "more" (for some definition) than the average humanities major's studies do. Fine. What I'm saying is - it takes a lot of arrogance to cast aside entire college departments as worthless.