I would generalize, as follows:

Allow anonymous posting, with a checkbox. Not really anonymous, you have to be logged in, but non-mods don't see ID.

Anonymous posts don't display until a mod explicitly permits them.

Special rules for anonymous posts: be very polite, be very on-topic or validly critical of another poster's delivery. Posts without extra effort to politeness beyond the norm will be summarily junked.

Result: this gives us criticism with no status modification, it also gives us posts with on-topic views which a poster might have good reason to disown in public, but still consider true.