John Fox is sabotaging his team.
They run a 1986 pro-offense consisting of I-formation and singleback on first and second down, getting minimal yardage. Then they run that ONE zone read play, without any modifications to it to keep the defense guessing. When they fail repeatedly with this scheme, it allows Fox to say that he's using a "college spread offense" for Tebow but it's just not working. The media certainly plays their part, with Thom Brennaman constantly reminding the viewer how little time of possession Denver has in the game.
Leslie Frazier, likewise, is sabotaging his team.
But, with him, it's just stupidity. Due to his inherent racism, he thinks of Gerhart as nothing more than a dive back. The playbook for Ponder is all short-yardage and horizontal. Very quickly the defense has learned to just bring everybody on every play because there's no chance of them getting burned deep.