Well if you get right down to it Tamiya does not really make a competitive TC..Tech makes it for them..
The only company other than Losi and Associated that made a good 2wd racer is Kyosho,And they lost interest in that,The problem I see in the whole off road scene is both the B4 and the BK2 are very very good and I dont think Tamiya,Kyosho or anyone else is going to come up with a buggy thats any better..maybe as good but not any better,Ever notice how much the B4 and BK2 look like each other,It's going to cost some big $$$ for R&D work for the others to reach the level that Losi and Associated are at now,And their is not much of a market their in the first place.It's not that they cant,it's more of a why spend that much money on a small market share.