You know, your point about sailing itself not being very open to newbies is a good one. As mentioned it's often a fenced marina, or a club of some sort, or expensive lessons, or even a regatta - all of which really limit who can play.
Are there any "programs" or whatever out there where newbies can hook up with willing, capable sailors to just go out and see what it's about? When we started, we just wanted to see what it was like - as would any newbie. But we didn't want to drop hundreds to do it (although we did anyway). The options are really limited as pointed out above.
Probably not an answer here. I mean who wants to take strangers out on their boats? But it might be cool for clubs, etc. to have "opens" if they don't already offer them so more people could be exposed to the sport. Because, you're right, it's dyin' unfortunately.