One of the challenges is how far from the core a place is. I am soundly in the suburbs. A few of the younger 'I want to go clubbing on Friday sorts' are not amused at the $45 cab ride home if they miss the last train/bus home option at 1am.
Yep, and the suburb I am in doesn't even have bus service.
In fairness, I think the OP has a good idea, but there are services already in place to do this.