I agree there is no way to know with certainty what would have happened in 2001 had Drew not been injured and remained the team's starter.
That said, It's not hate to conclude that it is more probable than not that the 2001 Patriots were not going to reach the lofty heights Brady led them to had they instead been quarterbacked by Drew.
In fact, based on the team's performance under his leadership over the previous 18 games, it seems an incredible stretch to try to make a serious case the team had any realistic chance to suddenly turn it around and perform under Bledsoe the way it did under Brady. IMO It's more likely Drew had gone from franchise savior to coach killer by that time. Even BB was reported to have been worried he'd be fired at the end of the year the way things were headed.
That's when fate stepped in and a legend was born. No disrespect or hate towards Drew to admit it.