You can get the answer from the same post ^^^ ... (no?)
Not everyone wants to have their entire life linked through a public profile. It is entirely possible to generate an anonymous set of unique pseudonyms. Systems such as digital e-cash and/or platforms like zcash enable the identity verifiers to issue anonymous tokens to users who validate their identity. These same verifiers can then allow users to redeem their verified identity token for a signature on an anonymous ID. The verifier would be unable to link the token to the real life ID and yet could ensure they never certified more unique IDs than exist. While an individual validator could forge anonymous IDs, it wouldn’t be practical to get multiple validators to forge anonymous IDs.