Because of bitcoin does not give public details of people who make transaction with it, some people do say it promote crime. People needs to understand one of the features of bitcoin is freedom that anybody can get access to it, it does not discriminate. The privacy features of bitcoin is very important to humanity, which I know one of its advantage is for safety by using cryptography that makes all transactions safe and encrypted.
Privacy in transactions of bitcoin is much important, if their was no privacy it would have cause several criminal attacks. For those who think bitcoin encourages crime because of hiding public data of users don't understand the importance of bitcoin being private. Before bitcoin started existing monetary crime have been existing. Bitcoin is not a reason for monetary crime, bitcoin is just for everyone and does not discriminate but accept everyone.
Anonymity and privacy is not a crime! Although Bitcoin is only quasi-anonymous and transactions could be traced down to an exchange account/address for example. There are some ways to avoid detection though by using Bitcoin mixers, Tor and DEX exchanges. Everybody should have a right to stay anonymous.
Whether they prefer to stay anonymous or not is upto the user. We shouldn't involve into it. As said it is possible to trace out transactions as it is possible to differentiate exchange addresses from the Dex and other wallets. This gives the access and if the transaction is made to an exchange it is an easy task for them as most of the exchanges needs complete KYC to use their platform. Crime getting connected with bitcoin is to destroy the growth of bitcoin. We were able to see a big number of crimes happening around and those were just crimes and shouldn't be connected with bitcoin or other cryptocurrencies.