The correct term here is pseudonimity - you know the immutable, stable wallet id of who mined the coin, which is a pseudonym for a real person. Anonymous systems are ones in which it's impossible to associate an identity with the work item.

For example, if I send cash through the post office, and I don't sign the envelope, that is a form of anonymous payment - it's impossible to tell who sent the payment (assuming there is no footage of the post box where I deposited the envelope, and I left no DNA on it, etc). If you receive a second payment, it's impossible to tell whether it came from the same person or someone else.