No but you gotta admit that bitcoin is especially well designed for illegal and or immoral purposes...
For the same reason it's a lot used in scams, it's probably used in weapons traffics and or prostituion/drugs.
Just because it's an easy way to transfer value anonimously.
To be honest there are other altcoins which provides much better anonymity than Bitcoin. Anonymity is not Bitcoin main feature.
Bitcoin main feature is decentralized public ledger which is just pseudoanonymous.