It's been my experience that getting good grades has very little to do with the quality or completeness of one's education.
I think that working hard is the path to success. And by 'working hard' I mean working with intellectual honesty -- doing work which makes you smarter and requires thought.
Adding fluff to an English paper to make it longer is intellectually dishonest. Copy+pasting selections from a Wikipedia page into a PowerPoint presentation and then spending an hour rearranging the words to make it look like you didn't copy verbatim is intellectually dishonest. These things are standard practice for 95% of all high school students and they are rewarded within the education system.
Yes I may get a good grade doing it the honest way, but it seems unfair to me that those being dishonest should get the same grade.
I'm not saying that intellectual dishonesty isn't possible in math or science, but it is certainly easier and in my experience, 'the norm', in the liberal arts.
I am happy to know that somewhere down the line this all comes back to bite you. This seems logical to me that striving to better oneself intellectually rather than striving to get good grades would make one a more desirable employee in the job market.