I think Danny has played the hand he was dealt the best he has been able. The hardest thing to do in sports is to rebuild after a contending team's window closes and the aging stars are finally gone. The fans become spoiled after years on top, they want every young player to be KG or Kobe right away.
The fact is once the Big Three were gone we were in for a long rebuild. I'd say the best comparison to the C's right now is the Lakers. Both were at the top of their respective conferences, had great players, and then the windows closed. The Lakers are an abomination with almost no future to speak of. The Celtics have some solid youngsters, oodles of picks, and cap space.
That said, the team presently stinks to high heaven. We're good enough to beat some bad teams in the East, but we get blown out by the true elite teams (Cleveland). The fact that a team 10 games under .500 is in the playoff hunt is a testament to just how bad the EC is. In the WC, this is probably a 20-win team. Ainge knows this, and that's why he's he's going to be super aggressive the next two offseasons. Don't get too attached to any of these guys because everyone is on the table. We need to get lucky to find the disgruntled star and get upgrades in the frontcourt.