I participated in high-level interdisciplinary courses in philosophy and science and philosophy and mathematics.

While I grant everything you've said, the lack of rigor cuts both ways. In my experience, many if not most who come from the non-philosophy discipline arrive with little to no respect for the philosophy half of the course. They enter with the popular conception of philosophy as something vague and contemplative.

What this leads to is that the non-philosophy participants get frustrated that the discussion seems to center on silly or archaic questions of metaphysics, as you have described regarding dualism. In truth, though, most of the archaic questions persist with more sophisticated questions and pushed farther down the rabbit hole.

Take dualism, for example. While dualism in the sense of the ancient and medieval philosophers has no supporters remaining, the ontological status of consciousness and intelligence is still a much-contested topic.

I want to emphasize, here, that I'm not talking about the causal status of various states of consciousness or that consciousness seems wholly dependent on physical processes and structures. These are trivial points and givens in a modern discussion of the topic.

The interesting question is not the basis or the mechanism of sentience but rather the phenomenon of the sentience itself. Even if a thought is entirely constituted by physical phenomena, it corresponds with a separate set of subjective phenomena which are not obviously physical -- our internal life and our awareness.

With no disrespect intended and with no pretense that my understanding of these problems is anything approaching complete, I've found that many who share your experience to not fully have grasped the essence of the given problem in question, often satisfied with an intuitive answer that, were they to more seriously delve into the matter, they might understand to have been powerfully undermined 2500 years earlier.

There's a reason that when most of the sciences spun out from under the label of philosophy, some matters of consequence and importance defied progressing toward that more solid ground.

I expect many would say that this is because the remaining questions are nonsensical. Despite my personal experience to the contrary, I understand this viewpoint. It is at least worth consideration, though, that the philosophical questions that remain won't submit to the scientific method; that's why they are philosophy. Many of the greatest minds in history struggled with these questions, for centuries, not because they were lacking in relevant facts but because they realized this special class of problem that seemed impossibly beyond any collection of future facts.

In studying philosophy, it's difficult but essential to guard against letting the absurdities of a given era's ignorance occlude the essential aspects of their arguments on questions that are still open. Usually those arguments prove to be quite relevant to the modern understanding with only minor tweaks to particulars.

*As an aside, please excuse me for placing all of this under your comment as I'm not trying to lecture you as much as present ideas in response to similar themes your anecdote evokes. I don't doubt that your experience is exactly as you said and that you understand the open problems even better than I do. Your writing, though, opened a more general line of thought that I wanted to express in reply to be seen by on-lookers rather than something aimed at you in particular.