Or to put it another way, Sallie Mae is doing exactly what lenders usually do: they charge more interest to people who are at higher risk of defaulting. If McIntosh College is the sort of institution that places its graduates into cashier positions at Rite Aid, then I too would be nervous about lending $20,000 to a McIntosh student.
The lawsuit is just about some lawyers trying to cash in. As a mechanism for social change this is completely inefficient. What would happen is:
1) Class action plaintiffs win.
2) Sallie Mae lowers its interest rate to the high risk group.
3) Sallie Mae (to keep making money) increases its interest rate to the low risk group.
Effectively you end up with the low risk group subsidizing the high risk group's student loans. Even assuming this is a desirable end goal, it would be vastly more efficient and fair to try to effect this change through the political process.
Class action suits have their place as an enforcement mechanism. They are a good way of, for example, forcing car companies and drug manufacturers to keep standards high. But they are not the appropriate mechanism for changing educational policy.