I am not a fan of a single point rating system. I have raced Nacras, Tornados, and Prindles. In the 90s, we used D-PN and I could tell you who would win based on the wind speed.
I get it... but users seem to demand a single number system across the board. There does not seem to be much user demand for more elaborate tables.
With a performance based system (PHRF or Portsmouth) the argument for wind speed ratings is stronger. This argument is mitigated by the realization that sailing in breeze on conditions requires more skill and perhaps the performance differences are overstated. Tis a valid debate in the bar!!!
For measurement based systems (ORC or SCHRS) they build in the non linearity correction into the formula. Again, the precision of the game and the skill level bump up in breeze make it difficult to evaluate how well it handles non linearity. Tis a valid debate in the bar!!!
All of the handicap tables are fair minded attempts to make a game of sailing diverse boats possible. YMMV.... again.... a valid debate in the bar!!