My 14 y.o. asked to fly gliders. Club fees were $400 and tows $50 each. His 14 flights cost $1100. This season his dues were $200 with tows still costing $50. He has access to club ships (1-23, l-23, 2-33) and has been offered use of a few private ships. This season he will spend about $1,000 to fly.

When he played soccer the club fees were $1500 per srason plus the cost of travel, lodging for tournaments, fuel, food, etc. soccer cost almost $5k each year. He played for 6 years.

As Kirk said, soaring is not expensive in terms of cash. The expense is time. As others have mentioned hanging out at an airfield in hot temps, bugs, snakes, and other critters isn't family friendly or even just hang out friendly. Add in risk aversion and from the outside soaring doesn't look like much fun. Flying isn't difficult but it does require dedication and consistency to learn. The lack of instant gratification doesn't help.

I don't believe expense is a barrier to entry. Do some research and compare the entry costs and participation cost to other leisure time activities. Something's besides money are keeping people away from having a go. Those who choose to spend money on any activity make a conscious decision to do so. Regardless of the cash outlay there needs to be perceived value in the expedature. To many, soaring might be low value even if it were free and thus not a valuable expenditure of time.

As society becomes more risk adverse anything viewed as risky becomes less attractive which is part of Gregg's original post.