"And as someone at York supposedly said...."in 15 years, everyone here will be dead". "
That someone doesn't know the current actuarial and epidemiologic data. Life expectancy at age 65 for males is about 18-20 years based upon old data, and it is my experience that the older data are unreliable. Even at age 70 the median life expectancy using those old data is more like 16 years, so they're at least off by a year 
, and that's a 50% mortality rate in 16 years (definition of the median), not 100%. Check out the obituaries online in the NY Times or your local newspaper for the sizable population of people dying in their 90s. Unheard of in previous centuries/decades. Good news if you prefer living as opposed to the contrary.
That said, people in their 80s and 90s likely spend much more on health care than they do on hobbies, so we'll have to wait and see what the effect of an aging demographic is on the hobby. Local college has a model railroading club and about 20-30 members under the age of 22. HO, of course. But that's where many of us started as young adults. The sky ain't falling, at least not yet.
