Considering one of their years of tanking netted them a guy that may never play in the NBA (Embiid), another year they missed out on a superstar (Towns) and got a consolation prize that has some warts on his game, and they haven't gotten the number 1 pick yet, can you blame them?
I think it's hard to argue that the Sixers methods haven't netted them a really awesome pile of assets. Okafor looks really good, Noel is pretty good, Saric is still fairly well regarded, and they've got a boatload of picks in addition to their own picks.
Embiid might even still have some value in the future, if say he finally makes his debut next year and looks pretty good. He could be a part of a trade package, at least.
The thing that I think the Sixers have overlooked is the human factor. They've screwed with agents, with players, with the league as a whole. That's got to affect their dealings, either now or in the future. And at some point, you've got to actually build a team. How do you even evaluate the way the players on that team perform? On some level, hasn't every game over the last three years been a pre-season exhibition for the teams involved?
The Sixers aren't setting up their prospects, their coach, their free agent signings -- really anybody involved in the organization -- for success. It's hard to say what any of these guys is learning about NBA basketball, let alone winning NBA games. All of that has to account for something.