is likely a continuation of what we've seen over the last century, only accelerated by the pace of society. Today's boaters are time-limited. Vacation cruisers have a clock ticking, and they tend to do things on a schedule. Sailing and schedules don't mix well. It's only the retirees (and other people who who for one reason or another don't need to "keep the plates spinning") who can take off without a schedule. Sailors on a schedule are more likely to sail closer to home, and/or charter.
Kids who didn't grow up in a sailing family are more likely to get into power boating when they grow up, if they get the bug at all. The career demands and jobs climate for young people prevent them from having much time or money to get into it on their own, unless they can do it with family money.