Time is the usually the issue. My son stopped playing soccer due to the time commitment. The ratio of play to windshield time was not favorable. Best guess is traveling to a soaring site or soccer activity is pretty much the same. Often we'd travel 5 hours round trip for a 69 minute game where the kid plays half. At least with Soaring you can travel 5 hours round trip and take a few tows to balance the travel to play ratio a bit.

If a kid or anyone travels more then 2 hours round trip to fly for 30 minutes my guess is it gets of real fast. At least they play soccer in the rain, winds we wouldn't fly, etc which can help with scheduling. If a pilot has only saturday to fly and the WC is not good or the op doesn't run the pilot is unable to get his fix. Sometimes they can trade days with family but if not they lose out. Frustration can set in and many claim the effort to reward ratio is not worth it.

Time and convenience are most often the controlling factors for participation in recreational activities. Circling back to Gregg's original question about modern society I don't think risk aversion in modern society is as big a deterrent to soaring participation as finding a solution to the time/convenience conundrum. The advent of little motors does address the time needed and inconvenience of a landout hence the rise in popularity.