I agree that someone can't be 100% certain all the time but there were cases that chain analysis led to child porn rings , especially in cases where the users were ignorant about how blockchains work .
If you treat everyone guilty until proven otherwise, then definitely, some of the times they won't be innocent. The question you need to answer yourself is if it's worth to live under a regime that is discriminating against everyone who is trying to have some privacy, for the sake of seizing criminals.
If a criminal mixes their coins with other people's coins, then are they all criminals?
As for the mixers , it's sad to see many people here claim that mixers is a tool to protect privacy , that kind of users that have nothing illegal to hide are just providing exit liquidity to criminals
I'm neither hiding an illegal activity by encrypting messages, but I do have something to hide; the message. Freedom of using cryptography can be exploited by criminals as well, but it is nonetheless a crucial, respecting part of our Internet world now more.
Why are you finding it so difficult to accept the fact that I may not want to reveal my financial activity publicly?