I think he's refering to 1/8 scale nitros...
I completely agree. I think its mostly due to the "basher" realm of r/c which I've been told makes up 90% or more of the total r/c market. In the last 10 years the shift was made to RTR's for the instant gratification everyone demands. Secondly no one likes buying the extras. Kits require a lot of components bashers don't think they need, but they do. Without them they end up dissapointed and put the r/c on a shelf in the garage.
I think you are going to be stuck with buying used rollers rather than new kits. Besides, a used roller will probably be the "Team" kit, just with a little better price.