If you want to take this further, one would argue that Cameron was a terrible head coach in the college ranks when he had his shot as well. Working with Indiana, the guy went 18-37 in his career with 0 National Championships and 0 bowl appearances.
Jimmy Johnson, who also went 1-15 his first year as an NFL head coach, had a 52-9 overall record and a National Championship to his credit while working in the college ranks.
Cameron is a great coordinator, no question about it and is someone I would love to see in Buffalo as a coordinator. But they guy just doesn't seem to be cut out for a head coaching job.