University of Toronto is also guilty of this. I've long since stopped caring about my GPA. I'm certain it's high enough to get me to grad school, which is my eventual goal, so I really don't stress about it that much. Also, I realized that I didn't have as much control over my GPA as I thought I did. TAs sometimes fukk your mark up, the Prof might change the requirements of a question the day before, the Prof might just be a lousy instructor who obfuscates relatively simple concepts. if you're really about that high-GPA life, then you have to have a hustler mentality. you have to be willing to do anything short of cheating, because it's very easy to lose marks for completely retarded reasons.
and as far as the purpose of grading is concerned, i prefer to think of it like this. if you have a high GPA then it's very likely that you're a reasonably smart fellow, grade inflation notwithstanding. if you have a gpa that's on the low-side, that doesn't necessarily mean that you're dumb as a box of rocks, but it's more probable compared to the guy with the perfect 4.0. therefore, you have to compensate for this with experience, or be able to sell yourself well.
when i was taking an algorithms class last term i was reading this really excellent algorithms textbook from a professor who apparently had a 2.5 GPA in undergrad. he's a really smart dude, but he cared fukk all about completing assignments when he was in undergrad. don't let grades define you but at the same time realize that we live in the real world, and it's really difficult to convince others that you are a serious, hard-working person when your grade is on the low-side.