"So a school that typically enrolls high-risk (of flunking out) kids may stop taking them in altogether; or just graduate everyone even if they are barely literate. That may not actually be better for the community that a school traditionally served.
For all we know, CSU-LA is actually doing a stellar job and has done the very best it can with the entering students that it is given."
For this reason, the USNWR rankings grade schools on how well they do actually graduating students as compared to what the expected graduation rate is given the demographics of their students. For example, UVA does a good job graduating 93% of its students when only 88% is predicted. +5
Duke is even. WUSTL is -1. MIT is -2. NYU is -5. Case Western is -8.
Penn State is +9.