I think you have to weigh draft position when considering a player a bust or not. For example, Porzingis at around 10 was a good value, but now that he's shooting up the draft boards (#3 on the new DraftExpress board) and some teams have even ranked him equal to Okafor , he has legit bust potential.
There is logic to the Sixers taking him at 3, because he will need time to develop, and they can be bad for another year and then draft a quality PG. They also have the rights to Saric. The Sixers are going to set themselves up well for the long term. You can hate how they are doing it, but they are patient, and going to stock up with a lot of talent. They will be the team to beat in the East in 3 years, and for a very, very long time....
Where would they play him? He's a 7'1 PF/C and they already have Noel, Embiid , and Saric. Do they actually consider Porzingis that much better than Russell or Mudlay or Noel , Embiid or Saric to use #3 on him?