I even hear radio and tv guys talking about this possibility. It just sounds crazy for Philly. They will get way better offers.
Lucky for them, I'd say.
He was not a good player last year, and has gaping holes in his game. He clogs up the middle, subpar rebounder, no outside shot. Grade D free throw shooter. Defense? Uhhhh... The Sixers were a bad team but they were ten points WORSE per 100 possessions with him on the floor.
If the Celtics got him they'd have to redesign everything around him.
He's young and does a few things very well. Can he grow and adapt? I'd bet against it. Better a flawed, diminished, expensive Dwight Howard (not that he's going to Boston, just saying).
I think you could do better with the third pick.