As with most things in basketball, its not as much about the 1 player as it is the net product. But Rondo is already under an ideal contract, so you build around him.
Rondo is the future of this franchise. But because of that, a non-shooting/scoring center is worse than he normally would be. On some teams, like OKC, Perkins is worth $9mil a year. Unfortunately on this team in 2012 and beyond Perkins is not as valuable, and could have greatly limited the product on the court.
This isn't about "getting Dwight Howard". But it is about building this franchise around Rondo who is already signed to an amicable contract. From there, the sky is the limit.