I think you folks have ALL hit on the reasons there are few people cruising (which is really what the OP is asking).
A) Cost, yes some junkers can be had for free, but due to time constraints and/or lack of skill, it's not practical to take on that kind of project.
B) Cost again! It costs money to tow a trailerable (gas), and most POS Prius type cars get great MPG (cause gas is stupid expensive) can't tow! Forget that if you go bigger, you need to pay for marinas, and insurance, and or luxury tax, registration, etc.
C) Skill - sailing is a sport, and requires time to learn (you see in A?) people don't have time
D) Kids learn today about instantaneous gratification (flip a switch and live in a new realm) the XBox 360 experience.
D) Speed - most people who DON'T sail don't realize that sailing can be FAST! It CAN be an extreme sport... In fact I'd argue MOST of the people on this site don't think of Sailing that way either (not a knock please don't mistake that - cruising is ALSO extreme, but NOT what we are talking about).
E) I am going to say it... SAILING IS DYING! It's a dying sport. It's dying because of A-D. Less and Less people are buying into it. Therefore less and less people are passing it along to their children (as a skill). It WON'T EVER go away, but it will certainly become a margins only sport (you know unless owning a power boat becomes too expensive for anyone - ie $7/gallon gas).
I submit that if young people think you have to spend $12mill to go fast (see AC-72), apparently they've never seen a foiling moth!
But you know for under $10k, you can still have a lot of fun: