I'm 28, couple railroading friends, one baby.
I concur with several points made. I don't recruit either, and I don't feel obligated to.
It's hard to fault kids or parents choices when trains are selling for $200-to crazy money, and a used video game is $25. Plus, video games can build cooperation and problem solving in ways a very budget layout could never do - lots of bang for the buck.
I also feel like the roundy-round layouts lose interest. Prototype operations have a purpose and attract a certain type of person, regardless of age. I think a significant number of airsofters or reenactors could come to the hobby to operate a model train in realistic manner.