Thibodeau has earned praise from all corners for his work with the Celtics defense during his two years with the team. He was given free reign by head coach Doc Rivers  to implement his defensive system, which he brought with him from his time as Jeff Van Gundy’s assistant with the Knicks and Rockets.
The Sixers fired Mo Cheeks halfway through the season and interim coach Tony DiLeo stepped down after a first-round loss to the Magic, and it has already been a messy off-season for the Sixers. Free agents to be Andre Miller  and Theo Ratliff  skipped the team’s final meeting and Ratliff took shots at DiLeo after their Game 6 loss to the Magic.
For a team looking for discipline and a defensive identity, Thibodeau would seem like an ideal choice.