I think Riley was a better professional when it comes to the job, and didn't always say things that was eye rolling. Trust me, it's okay to acknowledge that Riley was better at some aspects of the position. This is coming from a person who commented on his hiring thread that he'd be fired after 3 years.
Frost often says and does things that are easy to make fun of. "Best practice ever", "we'll play in Kazakhstan", etc. He and Moos guided Nebraska in and out of off field fiasco's such as attempting to dodge Oklahoma and firing up an Indiana team with his own words. Frost routinely makes his own situation worse by exuding his unearned confidence and having it backfire.
Riley, despite his failures as a coach, was at least professional.
EDIT: I'll also add that Frost is not shy about blaming his predecessor, as he did often early. Fans give Frost a pass because he inherited a flawed roster, despite the fact that Stanley Morgan and Ozigbo were products of previous staffs' and he has yet to find or develop players that are even close to their production. Frosts' best team at Nebraska was his first one.