I dont think real “desire to ride” has changed that much. I think more of the change is in accessibility and societal perceptions.
When I was a kid, ( a horseless kid whose parents could only afford a few lessons or trail rides for birthday presents) riding “english” had great snob appeal for social climbing parents of girls. In many cases the only athletic-type activities encouraged for these girls were riding, ballet, and maybe gymnastics. Yuppie moms and dads wanted their girls outfitted and riding in shows they could talk about at the Country Club. In the 60s-70s it was the height of Yuppie-ness and impressing the boss to climb the ladder at work and socially. Even parents who could barely afford it sometimes thought it was an entry to better things for their daughter. So there were a lot of kids (mostly girls) at h-j barns. Some really had the “bug” and wanted to be there and some were apathetic and everything in between.
Then society and economics changed. Horses werent the prestige they once were and the lower ends of the upper-middle class started getting economically squeezed harder and harder. Girls had many more options for activities and recognition. Suburban sprawl and costs squeezed out smaller barns where the less affluent could get a start.
There are still a couple of big “lesson factory” type barns around me. There are affluent families who quickly have their child in a program, with a horse/pony and showing. But there are still kids in the lesson program long-term, enjoying riding and horsey friends without showing recognized shows. I am glad to see that lessons with school horses are still available around me for horseless riders. I dont know if they feel pressure to lease or own, but I do know that a fair number continue lessons until they go off to college without leasing or owning. I suspect they will be our future reriders when their after-school lives are established.