It's complicated and a multi factor problem, in silly consultancy-speak
I am 46 and I finally did the paperwork for my license two years ago, although I had actually passed the exam back in 1989! I had been in and out of the hobby since then, never transmitting, just experimenting with SWL, receivers, etc. Even my professional life has been linked to radio (my first real job was to develop some control software for an AOR3000 in order to monitor outages in some UHF relays, and there wasn't so many people with some radio knowledge and software development experience). And some radio knowledge has helped me a lot. When WiFi networks begun to get affordable, some basic notions on radio communications and antennas made you look like genius compared to the typical "computer guys" trying to set up wireless networks.
So, finally, after I was asked to give a talk about SDR over Echolink, I did the paperwork and now I am active after all those years! Of course I joined URE. What I found was a community in which I am one of the youngsters, at 46!.
There are many reasons why amateur radio is slowly dying. First, how many hams were attracted to it by the ability to speak to people from other countries? Back in the Cold War era you could even talk to hams from the Eastern Block, even if they weren't allowed to tell you what the temperature was (a usual joke of the day). Today the Internet makes it cheaper and easier. And social networks take such a large part of most people's attention, it's difficult for most youngsters to take some interest on this.
People's attention span is decreasing alarmingly. I've heard with horror that TEDish talks are "the future of education". I understand that a short talk by a really gifted speaker, of which there are just a handful in the whole world, can be really inspiring. But how many Sagans, Attenboroughs, Feynmans, etc can you name? Still, science topics are often hard to really grasp, you need to put a lot of energy on it. Of course, there is that plague of recent engineers who don't bother to know what they are doing and just do a Google search, copy and paste a solution of sorts.
Getting into radio as a kid must be much more disappointing now. When I had my first (crappy) shortwave radio back in 1983 or so, you would be amazed at the sheer quantity of stations from different countries you could listen to. Later I was given a more serious receiver (A Sony ICF-5900W with SSB!) and it was rather easy to receive a lot of amateur transmissions, even using a simple indoor dipole in my room. Today there is a lot of awful noise. I remember I hated TV sets back in those old days, but now it's much worse!
Now, imagine that kid (myself when I was 13) playing with dad's radio to see what is that "SW" thing, only to find noise. Lots of it. A different question would be, of course, the language barrier. Back in the 80's there were broadcasts in every language you could imagine and it was so funny to listen to Radio Moscow or Peace and Progress boasting the spontaneous demonstrations of joy of the miners at the Red Square...
The generational gap is dramatic as well, and most hams have become "obsolete" in so many ways. For example: Imagine that a real catastrophe strikes. Could a network of phone or even CW based communications cope with the information flow? Not at all. It could be a marginal help in certain tasks, but nothing else. In order to be an effective force to be of real help in a serious emergency and make a difference, you need both people with "traditional" radio skills and people able to set up complex digital networks. Fortunately, the availability of cheap digital radio equipment, especially DMR, is making some people get acquaintanced with these topics.
Maybe the IoT thing can help spark some interest. After all, wireless communications are fundamental. But there is something I don't like at al in the whole maker community, and it's again the shallow approach we see everywhere. People copies, pastes, hits with a hammer if needed, and stuff kinda works.
But often the maker in question doesn't really understand what s/he's doing and, worse, is utterly unable to communicate it to a peer. So you see so many forum posts in which someone asks a question, not bothering to give any details of course, receives some more or less helpful answers and, finally, posts a "hey, I fixed it" without bothering to explain how.
When I was a kid, a pair of HTs was a terrific present. How many kids have you presented with HTs in the last ten years? If you did, how were the HTs received?