I've gotten back into astronomy after half a life away doing other things, not related to drug, sex and crap head-banging music. Like all hobbies it requires some committment, and astronomy isn't exactly one that brings instant gratification. This hobby like a lot of hobbies requires patience, time and study and some skill. These attributes aren't exactly a high priority for most younger folk, I don't think the 'art' is dying out, because most people discover it or re-discover it later in life, after all if you took a poll throughout most of the last 30 years or so most of the hobbiests were over 30, the majority over 50, same as today.
This smacks me as fairly static, if anything there are more people doing it now than ever, granted the population has increased as well (no pun intended), almost all hobbies are enjoying increased interest due to higher expendable income, and time ... although a lot of 'polls' say we don't have time, working too hard to pay off mortgages, HECS fees, kids, etc.... This hobby doesn't require or demand physical fitness, though lugging the 'kit' around the back paddock might qualify. The group of 50+ now, could be said to be past their prime and looking for something less physically demanding than say ... golf ...

It's done at night (mostly) and depending on your interest all day or all weekend. I'm looking foward to spending my time doing something I enjoy that is proven to be sustainable through out a person's life and doesn't 'die out' with the passing of time and age like a lot of 'hobbies'. Rock on the 50+s, I will be there all too soon, keep a rocking chair warm and can I use your zimmer frame to prop-up me scope ....