I, for one, agree with the OP's sentiment.
I forget which coach said it, but he said something like "You win a championship in this league when you have a top 50 all-time player, and 2 all-stars".
Obviously, getting the ultra-elite top 50 player is the biggest problem, but it also makes the biggest difference. Think of it this way; out of the last 12 championships won, I'm pretty sure 10/12 involved either Shaq, Duncan, or Kobe. Obviously KG was our top 50 all-time player. The Pistons were a freakish exception.
Frankly, Rondo is NOT that player and we need to do everything we can to get that player. The most likely way? Tanking and getting the #1 or #2 pick. Or trading Rondo along with some other talent we acquire in the draft for an elite player, like we did for Garnett. Teams that try to claw their way to the top end up in Pacers, Sixers, and Bobcats, Grizzlies, the list goes on, territory. Good enough to barely make the playoffs and never better. Maybe you look legit for a year or two, but then you come up short.
You also need a great, highly-respected player to attract other free agents. Again, I question whether other players respect Rondo like that. Ray and KG felt that way for Pierce. Does anybody think of Rondo like that? I doubt it.
Just look at how the elite teams have been formed:
Lakers - Drafted Kobe, Shaq through FA
Bulls - Drafted Rose, Boozer through FA
Heat - Drafted Wade, Bosh and Lebron through FA
Thunder - Drafted KD and Westbrook
Spurs - Drafted Duncan, Parker, and Ginobili
Mavs - Drafted Dirk
Lastly, Celtics drafted Pierce, and got Ray and KG through FA.
Rondo is just not on the same level as Kobe, Rose, Wade, KD, Duncan, Dirk, or even Pierce. Even in Pierce's old age it's questionable that Rondo is the better player.
And on the come-up, I look around the league and I can see Blake Griffin being that player in the near future. Guys will go to play with him, and all he needs is one or two legit FA's and he's there.
We need a guy like Blake, not like Rondo