I'm thinking Philosophy is not rigorous at all at some schools, and is just a lot of lofty opining. I have no proof or first-hand knowledge of this, but I get this from some people's description of their experiences of Philosophy classes. That may be why some people think it is intellectually inferior to technical subjects. My first degree is in Computer Science (Texas A&M University), and then I studied Philosophy (University of Dallas) many years later. I found the Philosophy we studied (original texts of Plato, Aristotle, Aquinas, Descartes, Heidegger) to be more difficult than Computer Science for a couple of reasons.
The first reason is that these were first-class leading-edge thinkers we were trying to understand. Aristotle is very densely packed with content, and we had to read and re-read passages to penetrate them. (Some think that the writings we have of Aristotle are actually class notes, and may not be a good representation of his lecture style.) The second reason is that even though Computer Science is an abstract subject, code is more concrete and graspable than a philosophical idea because you can compile and execute the code and see if and how it works. Philosophical ideas are either difficult to test (e.g. ethics) or practically impossible to test (metaphysics).
The first reason is that these were first-class leading-edge thinkers we were trying to understand. Aristotle is very densely packed with content, and we had to read and re-read passages to penetrate them. (Some think that the writings we have of Aristotle are actually class notes, and may not be a good representation of his lecture style.) The second reason is that even though Computer Science is an abstract subject, code is more concrete and graspable than a philosophical idea because you can compile and execute the code and see if and how it works. Philosophical ideas are either difficult to test (e.g. ethics) or practically impossible to test (metaphysics).