Rigor, etymologically, is a kind of stiffness. My rigor would be more like a strong, sinewy, supple feeling instead.
If we throw out the concept of rigor, what are we sacrificing, exactly?
*The idea difficult things are worth learning. That worthwhile skills come after a difficult process of mastering them.
*Problem solving. The student has clear instructions and can follow them. The task is highly structured, ideally. But students can't follow instructions either, it turns out. Even clear instructions turn out to be opaque. And do we want to judge students on ability to follow instructions? I would probably not have had success in a system that valorized instruction following over thinking. In fact, I did not do well until I got to college and realized my professors wanted me to master the material rather than follow bullshit instructions.
*You can't any longer say, just give me your best response to this assignment. The students will blame you for not being clear enough. For example, I gave grad students assignment to analyze a poem. They wanted to list all the rhetorical figures in it. They claimed I had told them to do this, but I had given them a guide to analysis in which the identification of tropes was only a small part.
*It would be fine to say that at a certain level, rigor is not the point. You wouldn't want to impose it on small children. (Except that small children can work hard too, and certain skills require you to start as a small child to learn them at all, like being a concert pianist.) Now we even want to infantilize "junior" faculty. Yes, they cannot understand the tenure requirements. At what point do you want to treat people as adults? Someone brought up in a system in which there is no rigor will then complain that the peer evaluators for an article are mean, for wanting to impose standards of freshman composition. The resistance to rigor then doesn't allow me to say there is an exacting standard for those at the very top.
*Then, the standard in rigorous fields will still be rigorous. The Nobel prize in physics still goes to a significant achievement, usually with some degree of "rigor." The abandonment of rigor, then, is hypocritical. We still want to do the best work we can do, and we still respect people who do things well. But we have to be so cautious about our advocacy of any kind of worthwhile achievement. We are implying that those who don't have those achievements are not as good. But we all know they are not as good (at that particular thing at least).