Gotta agree with you there. University, I find, is all about the amount of time you put into it, not your innate ability. Out of high school, the material becomes less intuitive and more specialized to the degree where, if you don't invest a good chunk of time in it, you're not going to do very well.
And really, I feel that a GPA is little more than bragging rights. I mean, people are impressed by 4.0's and all, but it's really just a number that's glossed over in resumes, and is rarely a deal maker or breaker unless it's below some threshold. People rely a lot more on the impressiveness you exude in your interview and on your prior experience than on your ability to get good grades when deciding to hire you, because so many employers seem to be taking the stance that GPA says nothing about your workplace competence.
However, it seems like academia heavily rewards you with opportunities (such as undergrad research and acceptance into graduate degree programs) even if you do little more than get good grades, so if nobody else hires you, you can stay in school forever as a broke, exploited grad student/post-doc/professor. :P