Lee could have been an all-time great player...if he had played for a different team. He had the football smarts of the greatest defensive players and also the work ethic. Remember in All or Nothing, after the last game of the season he was already back in the film room the next day.
I think if he plays for a franchise that knows how to have sustained success like a Pittsburgh or Baltimore, he probably makes the Hall of Fame...even with the durability issues. And maybe on those teams, his body wouldn't have gotten hurt as often because he wouldn't feel the need to go all out every single play. On the Cowboys, he knew he had to do everything so he constantly put his body on the line.