ND's bottom third of its students are going to have much better academic credentials than at most other places, especially when it comes to most state schools. The student populace tends to be a lot more uniform, since most folks at ND are generally going to be among the best of the best in their high school classes.
State schools will lower the bar for in-state students, especially for students who often times don't have any business going to college (not really a bad thing if you're willing to do hard work in a trade school).
The bottom half of students at ND vs some state school will definitely have a significant gap in terms of academic abilities.
That being said, you're also right, that ND has resources for its students that are easily among the best when it comes to career placement.
I've seen many a senior who barely squeaked by, go through ND's career placement, and actually get a very good entry level job offer. While it often times wasn't in the area of their majors, it was a good position that afforded many opportunities for advancement.
Andersen Consulting (now Accenture) back in the 90's had a very large presence on campus, and would hire just about any ND grad who was willing to learn, regardless of major or GPA, just as long as you were on track to graduate.
Sigma Chemicals (now Sigma Aldrich) also had a pretty good presence on campus back then, and would hire people with even a reasonable modicum of science courses in their course load, even if they weren't STEM majors.