Ugh....what part of -
"Its unique outsole is made especially for hard courts" did you NOT understand?

I didn't write this. It's on Adidas' own consumer website, viewable by the entire world.
Are you telling me that you know that Adidas designed the outsole on the Feathers especially for clay courts when they state clearly themselves that, and I quote,:
"Its unique outsole is made especially for hard courts" ?

So are you a shoe designer for Adidas or do you just have an uncanny ability to read their minds?
It doesn't matter that they work well on clay, the FACT remains they were DESIGNED
"especially for hard courts". Their poor performance on hard courts is mostly due to their lack of cushioning, support, and the fact the soles are not very durable so they wear out fast on hardcourts, and not because of the tread design.
My Nike soccer shorts and shirts work well for tennis, but were they designed especially for tennis? No!