"... you undermine the views you hold by being unwilling to stand by them."
This is the attack - portraying anonymity as cowardice. Fallacious argument through and through - an idea/opinion does not require a a government approved name and surname to be valid by itself.
Your point seems to be that anonymity should be discouraged so that censors are aware of dissent. I think all the murdered journalists, whistleblowers, Clinton associates and Epstein witnesses, and probably Assange as well would disagree.