both college and NFL. He had a great relationship with Bronco as a player (from what I've understood) so it seems he is just calling a spade a spade:
Bronco is a great DC. He is not a great HC ("bless his heart")
I don't attempt to decipher anything else from his statements. I wouldn't go so far as to say that he suggests Bronco step down/be fired.
My take is... if we don't have a better prospect for HC, we keep Bronco until such becomes available/apparent.