And don't forget that most of the Olympic classes only "survive" as dedicated Olympic classes. I think the laser is the only class that has a reasonable contingent of non-Olympic hopefulls. Maybe the 470 in Europe can be thought of similarly.

Why would any other class want to be Olympic? It has decimated participation in many classes, 49er, Tornado. Only Olympic hopefulls are tempted to these classes generally. The Etchells refuse to be Olympic despite being the most popular keel boat in the size range of the existing classes. This is because it would destroy their local club class racing.