The point is, 4 years or 6 or 7 is really not enough to conclude anything about the future. Yes, we can conclude that after 6 years Collins has not been the massive upgrade we hoped for. But can we conclude he never will be? I doubt it.
After 6 years of Fitz, 4 consecutive bowl losses and win totals of 4, 6, 8,9,7,6......we'd be in a pretty similar situation to where Collins sits. See the similarity? A peak in year 4 followed by a decline. Would you have predicted based on hindsight that he'd become the B1G COTY and win the West after these 6 seasons?
I wouldn't.