Simon,
I think you will find that the board aspect ratio will be so close that the Texel rating difference will be so small as to not make even half a point difference, same for mast height, sail area (all very close) and all the other factors that count. Any small difference in the rating would seem to have no impact on the quality of the racing and the boats seem very equal.
Currently the boats that you call F16 are running a rating difference of 5 points or so, hardly a close thing.
Now, I am sure Wouter or someone else will jump in here and claim that such diversity is what gives F16 the strength over the other tightly controlled rules and it will eventually win out over these draconian rule sets... But in all honesty, thats total bullsh*t and you all know it.