1- Lots of classes have rules to control the cost. When you let in organisations like Olympic teams, they can often find a way around those rules. The 20,000 pound mast I mentioned earlier is a case in point, but I won't tire you with the details.
2- So what's stopping the well-funded UK team from starting up Windsurfers Limited and making a limited run of super-expensive boards and rigs, each board meticulously hand made in carbon over Nomex honeycomb in a high-temp autoclave, and available only to certain sailors? After all, the Australian Institute of Sport set up a special company (Bike Technologies) for its gold medal winning superbike. I think the UK has done the same. These rich countries give their athletes an advantage. Fair?
3- Since, as you say, equipment is only a minor part of the cost of a sailor's Olympic effort, in the real world the sailors ignore the mass-produced gear from the big builders and buy the expensive stuff from small companies that specialise in high-end gear. It's been happening for decades in boats and it happened in boards when D2 was the new Olympic gear.
4- About "First, most windsurfers don't race, just bunch of weekend warriors at the local lake."
Well, WHY don't they race? Maybe it's because the racing gear is not suitable for weekend warriors. Maybe we should change that, not just accept it!
5- "Second, manufacturers not too excited in promoting 'one' board that works from 5-30 knots, and can be sailed by a beginner and a pro, they prefer selling 2-4 boards instead
that almost accomplish the same thing..."
Sure - but why should sailors and Olympic teams have to pay for the manufacturers to make more profit by selling more boards?
6- 'Still don't get what you're trying to say, I gave example of biking as a reference that it's
a Olympic sport and not OD'
I'm trying to say that only a very small percentage of keen cyclists race and Olympic cycling doesn't rate all that well on TV, so why assume that it is a better model than sailing's OD model?
7 - "If you follow any of the main FW events, it's the talent that wins every time, Antoine won few years back on a 2 year old board design, as an example..."
Two things; one, there's plenty of other examples that show that becoming Olympic changes lots of things in a class, and it's sailed by more full-time sailors in more countries, with more coaches, more sports scientists, etc. Secondly, if old gear is competitive that's great, but it must mean that there's not a huge advance in speed and therefore OD gear will not become obsolete quickly.