I'm sorry I can't agree with that first part. The person with the 3.5 could just be a better student, that's all. Hell, applicable knowledge doesn't truly begin to develop until you're actually in the real world and applying those actual skills, and if the 2.2 person is better organized, fits in better in their workplace, and is generally a better worker (which is not determined by their life as a student), then that 3.5 is meaningless.
I understand what you're saying and to an extent I agree, but I've been working in education long enough to know that two smart people can have grades situated at different ends of the rainbow, and it's way more complicated than simply who's smarter than who. Take note though, i'm talking about 2 people with comparable intelligence levels, but GPA & test scores is in no way an end all be all, nor is it a predictor of any sort.
As for wasting the parent's money, that's cause the parents can't brag about little Johnny's 4.0 to their friends. Just get the damn degree, once you're in the real world and you at least have a Bachelors, the whole damn game re-sets anyway.