It is younger people. Whereas young families might once have gone to places like disney world, provincial parks are now the cheap family vacation. Reliable GPS, weather forecasting and cellphones have also made previously "remote" areas very accessible. There are no secret places anymore.
But there were other benefits to camping as well. Small kids don't belong in hotels and restaurants -- it's a nightmare for everybody. And the process of getting them in and out of those accommodations eats up half the day.
And if you're camping, that itself becomes the entertainment, so the sightseeing side of it doesn't have to be as spectacular. Last summer we made our way across the northern shore of Lake Superior -- possibly one of my favorite places in the world. There are no bucket-list tourist destinations unless you count the Wawa Goose, yet it was just a blast and quite relaxing.
Uh, what???
Granted, it could be a matter of personal preference as well. I enjoy the outdoors, and my own cooking, more than the inside of a restaurant or hotel.
'Camping', in Canada at least, is now more and more about people driving an RV up to a park with boats and ATVs attached. If there ever was a golden age of gentleperson light-touch adventure in the outdoors it is certainly gone now.
It never really existed. People during the glory days still pooped in the woods. They cut down trees for firewood. They walked off trail. They stored their food improperly and then shot the bear that came for it. The rules against such things didn't exist then. They do now.
I think the problem is a result of a combination of tech as well as cheap camping gear making all of it easier, and the popularity of it with young people more than perhaps in the past.