The thing is he was drafted by the last dynamic duo as a character guy who would be the cornerstone and leader of their defense. By their own admission, they were trying to be ahead of the curve, think out of the box, and build an elite team around a great safety that would elevate the team.
3.5 seasons later, both Dick and Marv were gone. That doesn't correct the mistake, but it speaks volumes about the quality of the decisions they made.
Of course, it's not Donte's fault that he's just another guy at a position that has almost no effect on the W-L column when a team can't control the line of scrimmage on either side of the ball. It's not his fault that he's always been an undersized box safety and was poorly scouted as being something he isn't.