Model announcing the move right before the season began caused a major problem. A couple early injuries didn't help and as BB's methodology toom some buying into, a number of players stopped listening to him once the losing began. The wholw thing spiralled out of control.
At the time I felt Parcells waited to step aside to be sure Bellichick didn't get the job. The Giants at the time had a very young offensive line, secondary, some quality young receivers, defensive lineman and even a couple replacement LB's. They also had Rodney Hampton and a backup QB with SB ring, entering his prime. They were poised to be a playoff team for another decade until a) Handley mishandled a number of things and b) Dan Reeves cut all Parcells/Bellichick defensive players (those who didn't land in Cleveland ended up in Foxboro) and turned the defense into whipped cream.
What's amazing is prior to hiring Parcells the Pats were discussing a move to St Louis. 90% of the people who claim to have been fans since before Parcells got there are lying through their teeth.