The guy is 3rd string. I doubt that is the kind of thing breaking Bronco's career. I don't claim to know what decisions Bronco should be making regarding personnel. All I can judge are his results on the field, and the number of guys he's putting in the NFL, and the results of both those measures have been subpar.
Personally I think it's how Bronco picks his coaches, and so far, he doesn't appear to be getting the brightest and best. Either way, he's the man in charge, so the results are on his shoulders.