True. Often they are correlated. But correlation≠causation.

I do agree about "but I tried" not being enough to get the grade. Alas, *that* is a direct consequence of the flip side which I mentioned. The idea that effort *must* produce results.

Both "lack of results *must* equal lack of effort" and "adequate effort *must* produce adequate results" (and "more effort must produce more results") significantly distort perceptions of society as well as individuals.

There could be a paper in there for some sociologist (not you, I know it's outside your "field" :-)