This isn't an attack on your comment, which gave quality information, but I think it's relevant to the conversations linked in your comment.

Their definition of authoritarian is a contradiction to their actions and used subjectively. "I hate authoritarianism, so we should defederate to keep out the authoritarians." This statement is supportive of a fundamentally authoritarian action.

This is also why people who use the term "tankies" seriously are themselves deeply unserious. Their understanding of the topic is superficial at best and colored only by Western biases rooted in anti-communist propaganda. The concept of authoritarianism was itself a product of propaganda.

Saying "no" is authoritarian. Holding elections is authoritarian. Authority itself doesn't matter, what matters is who is in power and how they use their power to influence the world.

Some people recognize and accept this reality and then openly support the power that best aligns with their own benefit.

Anger at tankies is usually just a lack of class consciousness and ignorance based on a term that changes based on who you support and who you do not.