But there is a demand for P48. A handful of manufacturers still make models ready to go, and more make conversion wheelsets to run on the track. Granted, it's a tiny sliver of the tiny (2 rail scale) market of a minority gauge of O, but it can be found with little fuss nowadays. How many manufacturers make 17/64 scale stuff today?
Don't get me wrong, I'm all for running what makes you happy. I like trains and would have one of everything if I had the space and money! I choose to focus my efforts in 2r and the Kato N scale passenger sets. I am concerned too about the state of the hobby, being only 37, and want it to be healthy for many years to come.
I think though that for the hobby to survive we would need more reasonably priced modern prototypes. Many of us model around 1950, give or take a few years. Looking over model magazines of the period many modellers were also modeling then-current prototypes. The hobby's focus has remained on that period, but to kids today I think many of them would rather have models of what is running on the rails today, not something from 60 years ago. The time difference would be like a modeller in 1950 making a layout set in the 1890s, a definite minority even then.
I don't think kits would work very well for the mass market appeal. About twelve years ago, I worked in a hobby shop in Minnesota, and even then ready to run/fly/float was an easier sell than the kits, even the still available Athearn blue box kits. If an RTR model has an issue as small as a wheelset popped out of the sideframe, many people would rather return it than fix it. This isn't just a modelling hobby issue. In the car culture nowadays, customization is simply new rims and a lowered suspension and a stereo, all done at a specialty shop. There isn't the sense now of do it yourself, except for home improvement because of HGTV and the like. Maybe we need our own network?