The Celtics are further away from contention than at least half the teams that failed to make the playoffs.
Well, judging by the reaction, that was clearly a sore spot.

OK, I'm willing to concede that the above might be an exaggeration, but I don't think it's so hard to make the case.
So, as Sean Grande says, the playoffs are all about who has the better 1, 2, 3. With that in mind, compare Thomas, Bradley, and Zeller (or Evan Turner, if you like) to the following:
1. Durant, Westbrook, Ibaka
2. Hayward, Favors, Gobert
3. Paul George, George Hill, Hibbert
4. Bosh, Wade, Dragic
5. Bledsoe, Knight, Morris
6. Cousins, Gay, Collison
That's 6, so all you need to get to 7 (i.e. half of the non-playoff teams) is to include one of the following teams that has some combination of a current star, superstar prospect, top 5 pick, or a top free agent destination city with cap space:
Embiid, Noel, Top 5 pick
Wiggins, Top 5 Pick
Kobe, Randle, Top 5 pick
Carmelo, Top 5 pick
It's not so absurd or sensational to make the claim, is all I'm saying. Yeah, the Celts have Brad Stevens, and the franchise history. But NBA players by and large don't care about the history of a franchise prior to roughly 8-10 years ago, and elite talent is always better to have than great coaching.
Oh, forget it.
Anyway, C18, you always fight the good fight, and I appreciate that. You sees things differently than I do. You are audaciously, persistently optimistic and positive. I respect that. Keep on keepin' on.