Isn't a central tenet of model railroading that kids will be able to play with their toys with their kids???
Happy New Year,
ST
Sure, back in the old American Flyer/Lionel days. First, those train sets were really expensive. I was able to find the Lionel catalog that had the set my dad got me when I was 6 years old, in 1951. It cost $69.95, which doesn't sound like much today but is the equivalent of about $553 in inflation adjusted dollars.

If you were willing to spend $553 for a train set now, you'd get a lot better quality product. Back then, you paid list price for everything. No discounts, no internet, and basically no competition. If you wanted junk, you paid the equivalent of $150 for a Marx set. Lionel and AF were about the only game in town.
There was also the idea that children would always want a trains set and fathers would want to hand down equipment to their sons. Scale modeling was in its infancy and hardly anyone thought that trains would ever get better detailed than they were in 1951. Just the fact that it had a whistle in the station and could make smoke was considered to be state of the art and what else would anyone possibly want in 2008? Both Lionel and AF made trains they knew would be used mostly by kids so they were made as bulletproof as possible. They were mostly diecast metal and you could throw them against the wall and not break off any detail because there wasn't any that wasn't cast in. The idea of video games and slot car tracks was non-existant then so what else would young boys play with but trains?
I don't know what proportion of trains sets are still bought for kids but I suspect a fair proportion are by adult males wanting to relive a piece of their childhood. Most will set up a Christmas layout and that's it but other will progress to doing a scale layout. This is where we hit the Spectrum/P2K/BLI/Atlas Gold/Athearn Genesis models. There is tremendous competition between these companies to produce ever more detailed locomotives with DCC and sound systems and beat the other guy on price. All of these locomotives are made in China because it's the only way to stay in the price game. Most of these locomotives are well made but they get tested for about five minutes before they get shipped out. The 1951 Lionel catalog showed women running each engine up and down a test track and proudly stated that "each Lionel engine is hand tested for two hours". Any idea what that kind of QC might cost today? Now, they hope the assembly is right and that the customer is happy but, if not, they'll just ship out another one. The customer has become the QC tester.
So, it's not 1951 and the Lionel and AF we knew are dead and buried with a time where almost everything was done differently than what's done now. Some may argue that's why we're in the mess we're in but it really doesn't matter. We are stuck in 2008 and 1951 is but a distant memory.