What do you mean by "difficult" exactly? Difficult to be admitted to? Difficult to achieve A's? Difficult to simply pass classes?
What I find, as a public school teacher here in the states, is that the notion of a "C" being "average" has long since passed. Especially in affluent towns like the one I work in, with very involved parents, anything less than a "B" might as well be failing. I don't think that we are properly preparing students for college with this type of approach, yet, it seems this type of grade inflation, and attitude of "everyone is above average" seems pretty rampant in most colleges these days. I went to a small Catholic school nicknamed "St. C's" because the average student truly did receive the average/'C' grade that their work determined. This pushed me to work harder because I did not want to settle with "average" work.
Regarding Aliz'e, with the academic supports in place at ND, I have to hold him responsible. There are more than enough people in place that would be more than willing to do everything in their power to help him, but at the end of the day it's on him to put in the work and pass the tests.