With modern rudders, yes they should be excluded because they don't offer any hull speed benefit, but that is up to the rules. A line in the sand has to be drawn somewhere.
THEY SHOULD BE EXCLUDED BUT SOME JACKOFF AT ALINGHI SAID "HEY WE CAN GET BMWO DSQ'D BY BEING DICKS AND MEASURING LWL THE STUPID WAY!!!
And you wonder why BMWO as to go to court? Its the only way that they can ****ing get a playing field thats not even level - but there at all.