"Anonymity maybe?"

The Blockchain is definitely NOT anonymous. There was a misconception in the early days that Bitcoin was a anonymous given there is no certificate authority that ties you to particular addresses.

However, this may or may not hold as various entities pop up (e.g. Coinbase, Bitstamp) who may be subpoena'd

Mixing also doesn't work because you can apply taint analysis. Further, do you really want to mix your address with other dirty addresses? Who knows what they've been up to!