The whole concept of bitcoin is to be anonymous so if this can benefit that goal, why not.
Uhm, no, Bitcoin isn't anonymous in the first place, why would it be the concept?
The whole concept is what satoshi titled the Bitcoin Whitepaper, to be decentralized (
peer-to-peer):
Bitcoin: A Peer-to-Peer Electronic Cash System
Then read the Bitcoin white paper again, section 10 Privacy. It states:
The necessity to announce all transactions publicly precludes this method, but privacy can still be maintained by breaking the flow of information in another place: by keeping public keys anonymous.
A Coin Mixer can benefit this goal, since through exchanges it is possible that you can actually decrypt the owner of a public key. Coin Mixing prevents that.