Bitcoin mixers and coin mixers in general are only designed for criminals and are only used for criminals.
It's very sad that this forum allows ads from coin mixers. People representing them in their signatures are also supporting criminals.
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It's very sad that you did not understand the actual purpose of Bitcoin mixers. Real criminals do not need mixers which, by the way, are not that anonymous as you think. Their outcome can often be calculated if you invest some time and energy. They rather use privacy coins.
There are countries in which Bitcoin is banned and since Bitcoin is easy tracable as you already stated, users from those counties often need to add some privacy to do transactions.
If I follow your logic, then all Tor users are criminals too.