He saw how the play of a pure PG caused this team to slow its pace too much. He likes the way the team is playing without a pure PG. Grab a rebound and put let to a ball handler. Doesn't matter if its Pierce, Green, or a guard. Just get the ball out and go. I think he wants to stick with that formula with this group because it's resulted in the most success we have seen all year.
The pace was much slower when the team got the ball and instantly said "where's Rondo? he's the pg and needs to bring it up."
More likely he a) watched Rondo play often enough to know that not only does he make outlet passes when they're available and b) understands that the team's pace is slower without Rondo, not faster.