Alternate interpretation:

1) Rondo is full of himself

Rick Carlisle is a better pure coach than Doc Rivers: subs/rotation management, game clock managements, building and implementing a system to maximize his talents, etc. Doc's more of an inspirational father figure, a true player's coach. Rondo doesn't need "excellent coaching," because he had that in Dallas, his ego simply wouldn't allow him to bend to it.

Being egotistical isn't a bad thing, per se, it's a league full of big egos. He's repeatedly demonstrated that he's unwilling to put his personal preferences and desires aside for the betterment of the team or system, however, which is what makes him Iverson instead of Wade - only worse because he lacks that level of transcendental talent.

Which leads us to the true problem -

2) His game's glaring deficiencies and the evolution of the "pace and space" era means that he will not be a worthwhile investment for 29 out of the league's 30 teams.

Rondo succeeded in Boston because he was on the floor with 3 future Hall of Famers who were among the greatest shooters of all time at their positions, and had a coach who is one of the best motivators the league has ever seen.

That perfect storm of circumstance is unlikely to occur for the rest of his career. He remains a gifted passer, and he's still nimble with a quick first step. However, he's extremely ball-dominant and doesn't work well off the dribble, he can't shoot from anywhere at all, he's a walking foul-target in late-game situations, and he's hasn't been anything more than average on defense for 3-4 years.

The league's general direction is the polar opposite of what he found in Boston: it's a horrible fit for his very niche talents. This means that at any given time, the vast majority of teams will lack the infrastructure needed to accommodate his deficiencies as a player. If he swallows his ego he could still have a long career as a talented role player like Grant Hill or Vince Carter, but I think his days as a starting point guard are behind us, and if he thinks every time should bend over backwards for him like they did in Boston, he's going to be out of the league in 2-3 years.