Many (most?) of the students were actively pissed off by this.

I think a class like this in isolation is bound to be off-pissing, no matter how useful it is. University courses have the extra problem of forcing you to be interested at a specific topic at a specific time. Students learn to grind through traditional courses even if they don't feel particularly interested in the topic at the time of taking the course. That course sounds like tossing undergrads into something like the environment grad students are in for the duration, and grad school has a reputation for causing massive procrastination. Free-form problems need more spontaneous enthusiasm to come up with good approaches to, and bringing that up for a semi-arbitrary topic on command is harder than having it for a topic you are already interested in.

It'd probably still be learnable, given a whole curriculum of courses like this instead of just the one.