Well Northwestern's obviously a different case. Not only Chicago, but Evanston is particularly expensive.
$2,800 for a four bedroom amounts to $700 per person, assuming no one doubles up in a room.
I think you can argue $1,300 isn't enough or as much as it should be, but to say it won't even "cover the rent" is going to be false in roughly 95% of cases. And of course they have the option in almost every case of living in the dorms rent free.(Of course then they don't get the $1,300 as I understand it.)