Reaper takes that approach. It does not distinguish between tracks and busses - they're both just destinations. A great idea, IMO. Unfortunately, just about everything else in Reaper felt so awkward to me that I couldn't ever get into it despite repeated attempts.
I come from a hardware background, where tracks are tracks and busses are busses. I'm therefore accustomed to thinking of them as fundamentally different kinds of things. Also, I don't use the Console view. Ever. In Track View I can position a bus right under a track if I want to.
At the end of the day, I don't consider SONAR's bus implementation to be limited at all.
Well, OK, I'd like to be able to freeze busses. Other than that, no complaints.