Considering Bitcoin is pseudonymous, if that is the case, poorly informed criminals. Most criminals are smart enough to use cash, cyber-criminals will use Monero since it is, well known, has plenty of liquidity, and it is truly anonymous and private from the get go.

Using Bitcoin anonymously and privately is possible, but it requires effort and know how and it has a premium cost, I do not believe it is worth it when you have better alternatives in the market you can use easily.