What is actually being argued here is not any innate superiority of the engineering/science curricula, but the dilution and loss of rigor within the humanities curricula. That doesn't actually touch on which is "more important to society".
That dilution is pretty easy to restore, but not in the face of furious resistance on the part of politically inspired culture warriors who mistake rigor and academic discipline for social oppression. These are folks who not only couldn't pass freshman calculus, they're folks who resent being asked to. They don't do very well with Aristotle and Tolstoy, either.
In short, the liberal arts aren't dead, they're as vibrant and vital as ever. The people studying them may be worthy of the topic or not. The difference is that when that happens in engineering, they flunk.
“That dilution is pretty easy to restore”
I think you are partly correct, and partly mistaken.
You are right that enforcing rigor is not that difficult in concept.
However, if you actually sought to restore rigor to humanities curricula, you’d have fewer (a lot fewer) students paying tuition.
“Institutions of Higher Learning” are first and foremost money-siphons - they want paying butts in seats and prioritize that much more than they do the rigor of their curricula.
The mission of Academia today is to fleece the stupid, and accidentally educate the able.
How does restoring rigor fit into this? It doesn’t.