I think , there is a need of deeper understanding and story is quite different.
May be grey black mtf charts are created with the mind of flash photography. And may be ccds are more sensitive to bright highlights and they wanted to tame the lens.
If you look at above mentioned website and testing the new and old 24 mm lenses , You can find the lack of quality of gathering natural light which makes Leica a winner.
I want to understand , is it true to understand correcting a lens piece is done with the selection of resolution or selection of contrast first ?
If american , british and german media hadnt been to start to test the lenses with mtf diagrams , may be leica would be the old leica again.
If you look to the older noctilux tests - 20 years ago - , there was a deep drop of mtf graph at the middle of the test , leica deep U letter.
Now , imx.nl site publishes the results and the graphs are highly horizontal.
I am not saying this is not easy to do but may be it is not the way of a lens should be.
Result : MTF tests cant explain the textureness , surface details , 3D Effect , Color Quality , Bokeh Quality , but they explain only the sharpness of outer lines of a portrait.
So new lenses take big flat single tone , single color portraits.
By the way , I cant find any fault even at 1920s Leicas.
Julia Margaret Cameron took may be 130 years ago and they are matchless.
I will keep try to explain this knowledge everywhere.