One thing we need to understand is that they aren't going to spend so much money on the signature campaign if only innocent and fair guys were using the mixer, it is quite obvious they get massive income from hackers and scammers which is ultimately paid to the signature participants.
Is it impossible for whales to use coins for privacy?
If I had hundreds of Bitcoins in a single input, wouldn't I want to split them before spending them so that I don't tell my local coffee shop that I have millions of dollars available?