Instead, an illusion of privacy was promoted to clearnet users (that's us here in bitcointalk), while in fact our "cleaner" funds were used to bail out real criminals and terrorists. Because to a mixer, a clean bitcoin, is worth more than market value, so they were willing to overpay for it in the form of advertising. Come to think of it, the recent bust of Sinbad served as a reminder that mixers are in fact very traceable.
Do you really mean that mixers are exploiting the clean Bitcoin they receive from users who came through a promotional campaign on Bitcointalk to compensate for the dirty Bitcoin they receive from criminals on the dark web? This is a rather interesting theory, but it is also strange.
First, because this assumes that all of Mixer's clients from the forum are innocent people looking to protect their privacy, and that all of his clients from Darkweb are necessarily criminals who want to launder their money. This is not absolutely true, and it is certain that any information can only be confirmed by the mixer himself.
Secondly, assuming the first hypothesis is correct, this would lead to the conclusion that clean Bitcoin is equal to the dirty Bitcoin that is to be replaced, which does not seem logical because I do not think that an ordinary person who obtained Bitcoin legitimately would be interested in mixing millions of dollars.
Thirdly, this forum or any other place would not have allowed this or would not have discovered it, especially with the multiplicity of tracking methods on the blockchain and the companies that have become specialized in this, able to track many transactions and verify their source.