I hate the anti-Reggie Bush argument.
The Saints aren't a vehicle to advance his career. They used him how they saw fit. And in fact, the role they carved out for him was so good that the offense was extremely successful when he was there and he contributed to a Super Bowl win.
And now he's running like a more traditional RB and somehow he's EVOLVED? Like he was a bad back in NO and now he's put in the work? No. That wasn't his role.
He always had the potential to be an all-purpose, featured back. The Saints just didn't need him to be that at that time, so he wasn't.