Yes, but those rules existed before you decided to participate in that race/class. Although having said that, what is happening with all the debate about banana boards in the A-class cats...early on boats were built to exploit the old rules which were changed to ban them (tip separation rule introduced from memory). It has happened in the moths as well (dihedral foils were banned, albeit through an interpretation and clarification of existing rules).
Rudders haven't always been excluded from LWL measurement. I can point to one international keel boat class that I'm fairly familiar with that includes them. A quick look at the 12m class rules indicates they also include the rudder in waterline length. Although that is a very hard rule to interpret.
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.
Back to some points I made earlier, what is Alinghi supposed to do? They can't predict the future and BMWO are very unlikely to give them all the plans for USA...
BMWO thought the rules
did exist and this is one point of contention. It's an absurd situation for the defender to be able to change the rules at will completely absent of any consent on part of the defender. It makes the entire Deed meaningless. At some point, there have to be stationary rules and BMWO had figured the rules in place at the time of the challenge would BE the rules. They didn't knowingly design in a vacuum.
What has screwed all this up is a very questionable ruling by Kornreich that gave Alinghi free wheel with the rules at any time. It would be like a French soccer (football) team going to play a match in Spain to find out at suddenly that spain was playing with different rules that include a physical 5'6" height limit on the goalie...and his height was measured including his shoes. It would be just as ridiculous a situation as what we have now with Alinghi's rule.
Who should really be ashamed is the international governing body that is supposed to oversee the rules...the ISAF.
