In theory, the rule of law will protect your right to say what needs to be said. In practice, you may have things to say that could be damaging to your career,

In theory, the rule of law will protect your right to say what needs to be said. In practice, you may have things to say that could be damaging to your career, or that may anger powerful interests, or even your government. That doesn't mean these things aren't worth saying. So anonymity allows you to say them without being prosecuted. (Unless of course you're making a distinction between anonymity and pseudonymity. Pseudonymity is a special case of anonymity, and requires anonymity as a base condition.)