I think people are taking it the wrong way. I used to subscribe to R and T for many years, I stopped a couple of years ago because they decided to make it 'edgy' and it lost its appeal. Car magazines often had a quirky view towards cars, one of my favorite columnists in R and T, Peter Egan, often wrote with a sardonic eye at his obsession with cars, especially British sports cars, the joys of unfreezing rusted bolts in a freezing garage, the mysteries of the wonder Lucas electric system (ie might prince of darkness), like 'why am I doing this, am I nuts?".
I don't think he is disparaging trains as useless, I think he is talking about the views of those outside either trains or sports cars that see them as useless. Trains and cars share a lot in common actually, the time we spend on the layouts and the money of course, but also in the diversity. Like with trains, there are those with sports cars who are obsessed with everything being perfect and original, matching numbers, original paint, every nut screw and bolt perfect (kind of like rivet counters in trains). There are those who enjoy driving the car and will modify an older car to put things like disc brakes on it or the like (kind of like those who modify rolling stock, repaint it, put details on it etc, basically operators), then you have those who go extreme.....or those who are happy that the car runs and it might not be 100 point or even 50 point......
And yeah, there is a parallel in both worlds with attitudes towards "outsiders". There are the car people (the 100 pointers) who if you look too closely at the car they will accuse you of damaging it, then there are those who are proud of the car but are okay if you get close or touch it. There are train people at shows who treat anyone there as the enemy, especially kids, and you kind of wonder why the heck they are there, then there are the many who are generous and yep, actually create layouts that kids can do something on.
I think the author was using trains as a way to reflect on his own hobby basically.
There is also an interesting parallel between model trains and cars, and that is the future of both. What we all knew as car culture, the way many of us were, is changing. We grew up where we couldn't wait to get a driver's license and a car, it was ingrained for many of us (kids who grew up in city areas were a bit different, depending on which city). The magic isn't there with young people, lot of them see cars as a utility, not as magic or freedom, a not small number don't bother getting driver's licenses even. And yes, there are young people into cars, the car culture, who love a variety of cars, it hasn't disappeared, it is just different. I would argue like trains, especially our niche, it is becoming less mainstream among the young but of course there are young people in it still, there are weird mini cultures like young people into the 50's vibe but with their own twist on it, which I guess is like people younger than like 70 with steam engines, both groups were born or became aware after the target of their interest was gone.