I just don't know that Fultz was a mistake. He seemed like the right fit (of course so was Jrue Holiday as it turns out. Heck the player they thought Fultz was going to be has still been missing from this team.). The mistake was getting fooled by the Celtics (in two different ways if you also think the Sixers should have picked Tatum to begin with).
The fact that Ben is still the second-best high pick of the era is crazy.
I don't think you can leave Brett Brown out of the equation either. Good enough coach but he's really the one who should have known better about Ben, either in the first place or towards the end.
I do think it's better now with a decent GM and coach who actually are in charge. It's a star player's league but for a few years there the chain of command really was Harris/Rubin straight to the locker room (or whatever party the players and owners were at together). Unfortunately there is little chance of an ownership change or culture change a la the Phillies or (hopefully) the Flyers.