I wonder if tor has been cracked though.
If an attacker wanted to they would be able to (assuming they had enough resources). All they would need to do would be to create enough exit nodes and entry guards and they could pull off a timing attack on most users.
I would say that bitcoin would be much more difficult to trace, especially when you use services like bitcoin fog and bitmixer and considering the fact that you do not need to actually monitor an address to receive funds to it and the fact that any people have legit reasons to monitor addresses they have no connection to