Generalizations are such fun; when you say, "The intellectual rigor just isn't there in any humanities classes because most of the students shouldn't be in college at all" I think you are conflating rigor with substance. Computer Science is easy but tedious if you're a Math major as I was. On the other hand, Native American literature was anything but easy because it required the clarity of a different world view as well as being able to write about it within the reality of the "inside-outside" nature where much of the literature originates. That understanding and the ability to write well is a rigor of its own.

I don't know, rigor is really hard to define outside of sciences, and even then, a science can be not as rigorous as others and still tell you useful things. I mean, economics isn't quite as rigorous as physics, but it's still useful.

One of the hardest but most rewarding classes I took in college was creative writing. There's not a ton of "rigor" to that; a lot of it is really subjective, and even with the widely agreed upon rules, there are certainly times when it's useful to break them. But I learned a ton from that class all the same.