Just because there isn't one person standing out now doesn't mean there aren't many that could take over.
Think of all the former players that are coaching. Sometimes there is a diamond in the rough that no one has considered. No matter who is chosen as the next coach it is never a "sure thing". There is always a learning curve and always a risk with any new coach.
Keeping Bronco in just because nobody else stands out is illogical. Bronco is in because he is a good person, not a good coach.