Yes that is a valid point; however when it comes to transactions on the Monero blockchain there is by design no option to not mix. This makes Monero fundamentally different from Dash and also fundamentally different from some other Cryptonote coins. This is important because by enforcing anonymity at the protocol level certain attacks can be eliminated or at least mitigated. There was extensive discussion of this in https://lab.getmonero.org/pubs/MRL-0004.pdf.

Publishing a view key is in many ways analogous to publishing a financial statement. The data is inherently anonymous but one explicitly chooses to make it public or share it with a certain group (those to whom the view key or the financial statement is provided).