First point... these are two different games we play. Very similar games but you play them slightly differently.

By it's very nature it's inaccurate.

Nope.... to make that argument... you would have to show that Sailor A who routinely just edges out Sailor B in a regatta on one design. Suddenly starts loosing to Sailor B. Your argument would be... the XXX rating system for these two class boats is not accurate. (I have NO examples of this occurring... fact is... the pecking order is about the same in either game)

I think what you want to argue is that handicap racing (and xxx rating system) is NOT AS PRECISE at sorting the pecking order by sailor skill. The analogy would be... two archers shoot bulls eye..... and are tied on points... One archer clustered his shots in a quarter ... while the other one filled the entire bulls eye. You would say... the test of skill could not resolve which of the archers was better that day. Next time... make the bulls eye smaller! (increase the precision needed)

IF you could get valid data... the statistics of signal averaging could get an extremely accurate rating.. of course that is a big if..... AND ignores the fact that you are comparing two slightly different games. My point that sailboat racing rules...(starboard has right away) CAUSE a good bit of the loss of precision in both one design and handicap racing..... So, Focusing on the accuracy of the ratings while ignoring the noise in the game is usually misguided. We actually KNOW how to manage this problem. We play the regatta game.... We spec out a fixed number of races to count . AND a fixed duration... with a fixed number of throwouts. (of course... all of these paramaters are heavily debated in coming up with the best game to sort out sailing skill)

Setting aside the details... here... I would support these statements.
One design racing is a more precise game to sort out sailing skill at an event.
It is VERY Difficult to get enough data to use the statistical power of signal averaging....the ratings are not perfect...
It is also very difficult to write a perfect formula. the ratings are not perfect.

Your conclusion.
It's a close swing at leveling the playing field and that's all. If you don't accept it as that, you won't ever enjoy it.

Is a very nice bottom line conclusion and I agree with it completely.