Wrong.
It's like saying Shula did nothing without Arnsparger.
Team sports are a collaboration between players and coaches, but their success usually depends on the leader, the man in charge making the decisions. Shula was an a**hole but he was a great coach. Parcells wanted to stay here but Kraft drove him away, and Bill wanted to keep coaching, so he went to the Jets. Belichick is one of many players and coaches who were integral to Parcells' success, who were there in the first place and did well because Parcells gave them the opportunity.
I despised Parcells for years because he coached the Giants. It's entirely irrational, subjective and lacks any substance, aside from Bill being egotistical but That's How People Are (And Have To Be) Living In New York City, and most players and coaches will tell you that Parcells' personality motivated and inspired them to do their best.
Patriots fans hate Bill today because of how he left. Even if Kraft hadn't thrown his tantrum and Parcells didn't leave, neither Bill nor Perkins was giving the ball to C-Mart and thus we weren't winning the Super Bowl. Coaches make mistakes - Parcells, Berry, Belichick - all of them.