I am holed up due to the blizzard here in Boston and thought I would check in on this thread to see why it remained so active. I didn't realize there was a throw down of sorts going on.
Let me try to sum it up. Drafting is like a box of chocolates (to quote Forest Gump). Sometimes it works out and you draft Durant, Westbrook, and Harden and sometimes you draft Greg Oden or in the worst of all possible outcomes, Len Bias (tragedy far beyond the implications for the team of course).
The Sixers tried to play the game thinking they would get maybe a mix of a few like Harden or Durant and maybe a few that bust. Embiid was a risky pick, no doubt. They knew injury was a risk and he missed two seasons and much of the third. Window is about closed but there is still a slim chance. Ben Simmons seemed like a lock but he missed a whole season. That is just bad luck. Okafor and Noel, seemed like sensible picks, haven't work out (Okafor has a chance still).
As far as how the outcome for Philly impacts what the Celtics have done and may do relative to building through the draft, you don't know whether we will get Durant and Westbrook or Oden and Embiid. We have enough picks though that unless we are really unlucky, some of them should work out and be foundational players for us.
It is wrong to conclude that you can't build through the draft just because it blew up for Philly. You can build through the draft, there is no guarantee or course, there is some risk, but that is the hand we have to play right now and at least we didn't have to tank for 5 years to get here. We still may trade some picks, who knows, I actually think not at this point.
I am excited to see a team of Smart, Brown, Fultz, Zizic, and BKN 2018 in the conference finals in say 2020 while in the meantime, we are a competitive, entertaining team. And I couldn't care less how things work out for Philly.