Look at J-Bar hobbies. They carry one line- forget which one, that carries several business twins. I know they have several of the Cessna twins, and maybe a Piper. The Testors Learjet is still available, and a handful of racing and aerobatic planes.
I also deplore the absence of civil aircraft, but most of my peers have no interest in them. I particularly wish there were good kits in 1:72 of the DC-3 and Ford Tri-motor. These are icons of the birth of commercial air travel. I like to build golden age civil aircraft because this stuff advanced the state of the art. Civil aircraft in the late twenties and early thirties were ahead, as far as tchnology, of the military stuff.
I have been to contests where all the aircraft categories were by allied or axis, and which war. Civil aircraft was shoved in the "misc." category. So it isn't just the mfgs.