It seems to me that ChioMixer was a genuine effort for Bitcoin privacy, while Sinbad was an operation made to mix the operators legitimate coins.
It could be. If
the bad guys were in charge of Sinbad, that explains why they were quickly trusted enough to send them millions of dollars worth of Bitcoin. Pretty much anything can be used for good or evil, but starting a business for evil is very different than a legitimate business being abused.
It made me curious about Tor:
~ a small fraction of users globally (∼6.7%) likely use Tor for malicious purposes on an average day. However, this proportion clusters unevenly across countries, ~