NPV is more sensitive to major than college. A Berkeley liberal arts degree has lower lifetime earnings than a Cal State nursing degree.
That's true, but if your model of using the list is "someone is looking for advice on how to make money by going to college", it is a desirable feature. This person doesn't know what they want to do, and funneling them to a school with only good options will guard them against choosing a bad major later, when they've stopped looking at the list. Adjusting ROI to major availability would make the list less accurate.