In a perfect world, I would agree with legiteum but in this real world
If we lived in a perfect world, there would be no criminals. If our perfect world had criminals, then they would be "perfect criminals", so the idea that money spent to catch dumb criminals (e.g., those using bitcoin as medium of exchange) would hold even more water than in the current world.
The fact is that big criminals have long abandoned bitcoin. They use monero and cash. The biggest criminals, however, are historically the issuers of the fiat currency.
You are right, perfect word is not really the best word to use in this situation, maybe it would be wiser to say
"in a better world". But it's still true that governments take law to earn more from taxpayers and in reality they don't do it to guarantee their safety. There are many valid reasons and proofs this argument of mine and I've already posted one in my previous post.
A few minutes ago, I was thinking that Bitcoin blockchain is accessible by everyone, right? If I share my Bitcoin address with someone to receive a payment, they'll be able to check my transaction history. I can't hide that history because blockchain is available for everyone for free. Logically, I should have the right to do everything to protect my privacy, including CoinJoin and mixing to hide traces because what if someone finds that particular address belongs to me and tries to rob me?
why not using a new wallet adress -> you have your privacy..