Those aren't classes. They are class theater.
They probably failed even by the simple arithmetic that the time required to make a minimally good faith effort at applying a grading rubric is greater than the time a teaching assistant is paid to "assist" in the grading.
Your teaching assistants almost certainly scaled back their time grading your assignments to fit their allotted hours. If any of those intro classes fulfilled a writing credit you can probably start with available undergrad writing credit requirements, figure out how many hours your TA got paid, and look back at the number of students for a given TA to figure out just how much money you and/or your parents lost on the deal.