Absolutely not.
People who think he should be fired don't understand the NBA. It is by far the most difficult league to rebuild in. Because of the cap, difficulty matching salaries in trades, the lottery, and the luck in getting "lucky" in winning the lottery when a franchise altering talent is there, the NBA is the hardest league to rebuild in.
Think about the C's tanking in years past with the best odds at the #1 pick, and ending up with what 3 & 6 the Duncan year, and #5 in the Durant Oden draft? That's brutal. Look at Cleveland with 3 #1 picks in a couple of years, and had they not signed Lebron they are likely still a lottery team. So much rides on forces you simply cannot control. Further add the difficulties in creating, or maintaining cap space, and then enticing a FA to come to your cold weather city over the likes of LA, Dallas, and South Beach. In the NBA you generally win with high end, elite players. It's hard to find those guys at the tops of the draft some years, never mind at 16 and 28. Danny is doing a terrific job to be honest. He's basically made moves to acquire as many scratch tickets as possible. To amass nearly a dozen 1st round picks over a 5 year period is truly unheard of in this league. The part that he can't control is where those picks end up being, and what value they will have to other teams. Case in point Charlotte yesterday. If he offered three 1sts to move from 16 to #9, he did more than I would have probably done. The problem is, Charlotte wanted Kaminsky more.
The one thing Danny can do, or can control more so than anything else, is tanking. He can't make the Celtics lose, but he can put together a team that wins fewer games. For example, keeping a veteran like Bass around this year, or trading for Jerbeko and Datome, then Thomas too, probably netted the C's the handful of wins that propelled them into the 8th seed, as opposed to missing the playoffs and picking around 9 or 10. At the time it might not seem like a big deal, but come draft day, when luck (or things you can't control) become the reality, it ends up costing you a Justise Winslow or Myles Turner. Maybe those players bust, and Rozier is the real deal, but how much better would C's fans feel today if we had Justise Winslow right now?
Overall, I think Danny understands the dynamics of the league as well as any GM around. He has a good eye for talent, and has quickly amassed a sock full of scratch tickets he hopes to get lucky with. There is no magic bullet in the NBA unfortunately. You really need a lot of good fortune. Danny has at least raised the odds for us with his moves to date. So far, we just haven't gotten very lucky.