It'd be fine with me to keep Riley, because I actually do think he could get to 9 wins on a fairly consistent basis. However, I don't see him every doing better than that because (a) he never has, (b) he doesn't have great coordinators, despite years in the profession to identify them, and © his system is fundamentally flawed in terms of producing consistent results, let alone championships, in a place like Lincoln.
But, .700 football while running a clean program ain't bad. So I'd never advocate firing him if he got to that level of performance.
Unfortunately, the hordes who pushed out Solich and Pelini will want Riley's head, too, and I'd rather we just make the change now before we possibly set NU football back further.