Earlier quoted context omitted.
These are all terrible uses of Bitcoin, as mentioned in the OP. All transactions are publicly visible in an immutable database. With a little investigation, law enforcement can find out who owns certain accounts and trace transactions very easily from there. If you are a criminal, you want no paper trail whatsoever, which is why they use paper money.
Bitcoin is pseudonymous if you take enough precautions i.e. always use tor, only use addresses once, coin join everything before converting.
You are right though that you can take measures to make it much more difficult to trace.