Interesting thread. Age of windsurfers seems to vary depending on were you live. I live right on the coast in the north west UK, and there is a 50/50 split between the under 20's and older. The sub 20's seem to look for flat water for freestyle or they chase waves. Understandable when you see the next gen PWA freestylers doing there thing.
On a windy day, we can get as many as 70 plus sailors out, ranging from 8yrs to 70yrs. This year, I have noticed a lot of people returning to windsurfing after a 20yr break (work/families/moved away from the coast etc).
The UK has a very healthy T15 race scene for the under 15's, and our local T15 is buzzing at the moment. These young racers are also into there freestyle, and a few are into waves.
The UK also has a pretty big UKWA race scene. Whilst there are older members, the majority of members are sub 20yrs old.
Our local windsurf school is consitantly busy, especially at weekends and on school holidays, its not unusual to see fifteen plus pupils out on the water. Admitedly, only a few will stick with it and move on to higher levels.
But what Im trying to say is that, at my local beach, there is definetly young, older and newbies. Plus most windsurfing companies still seem to be making money, so business must be OK!
Just my 2 cents worth