You're probably right, but it was actually my daughters (in particular 5 year old Emily, our Thomas obsessive) that got me back into it.
I think kids like having something tangible, hence the popularity of proper Lego still. Virtual things lack something.
I still prefer real board games. :{)
One interesting thing is that Airfix (owned by Hornby) seem to be doing well, at least as far as releasing new kits goes. My interest in building plastic kits was recently rekindled after about 15 years when Gaynor got me a Battlestar Galactica Viper a couple of Christmasses ago. While I'm not building them at the rate my teenage self did, I've done a few others since then, and found that somewhat inevitably there are vibrant, informative and irredeemably geeky online communities devoted to the subject. The general concensus is that most of the new kits that Airfix are releasing are very good indeed, and are competing well against the far east alternatives, not least because exchange rates mean that the prices of the big Japanese brands are getting ridiculous.
I'm not sure if The Kids are buying them, but there seem to be plenty of middle-aged men with disposable income enough to buy multiple copies of the kits that interest them, and the time and inclination to spend hours arguing on the internet about the exact shade of sky blue used on the underside of Spitfires on July 17th, 1940.
I think I'd find building airfix kits kinda therapeutic. But I wouldn't know what to do with them once they were built.
I can't decide whether suggesting just destroying them once you've built them would be sensible advice or not.