Indeed, few of my students in college STEM classes (in a university with rapidly increasing competitiveness for admission) have a solid understanding of the concepts contained in algebra 2.
This thread and
this thread both address the idea of watering down content so that everyone can pass a course.
By going through ST Math (a manifestation of CC math forced online) rigorous = tedious. That's (hopefully) not what the ed speak people are thinking.
IMO, "tedious" is used to hide the truth, which is that they don't want the course to be too "hard" and therefore not accessible to everyone. Who wouldn't feel bored (and unhappy) when stuck in a class addressing stuff you don't understand?
Personally, my solution would be to offer honors and basic math courses. The honors courses would be harder and would work through difficult material. The other students would do an easier course, but this fact would be acknowledged so that no one would be fooled, and the kids would get exposure to important mathematical ideas.