Franck, see my post in the other thread. Maybe some time in the good old U.S.A where we still have some freedoms would do you good...
Yes, the intent was probably never to spend gobs of money on design and cfd, but that is what has happened already (and I bet most of the CFD was done for low cost because most all the designers sail these boats, so have an interest in building the fastest possible).
Continuous upgrades with respect to sails are in the best interest of the class as a whole. Otherwise you get sail designs that are 10+ years outdated!!! Do you still want to be using a pintail sail on your F18???
You have to buy new sails every year to be competitive anyway. Why not have THE OPTION to buy sails that are lighter??? If you feel heavier sails are more durable and will last longer, then that OPTION will still be there.