"let's say it was small catamarans and those catamarans had a network like the Optimists have."

That is a VERY big IF, IMO. We have enough trouble trying to keep a regular cat group going. Sure, if we never start we never get there, but that is a HUGE goal to hit for a bunch of minority-group sailors. If I wanted to sacrifice my time, would I want to sacrifice MORE time to start a whole new group, or would I just take the easy option? Well, you already know I'm a lazy selfish bastard; I'm gonna dump 'em off at the dock and sit at the YC bar while they sail Optis. I'm sure not gonna build 'em a boat. Again, some people do all that; more power and great respect for them. Most of the people I sail with aren't that motivated. I've never had trouble stealing kids off Optis; it's the 30 year olds who are hard sells.