Uh, I don’t think you understood their point. Tankies aren’t communists, they’re authoritarians with a red paint job. We’re not talking about nuanced Marxist thinkers, we’re taking about people who think “Just line everyone who doesn’t accept my exact interpretation of communism up against the wall” is rational praxis.
This is the original comment I replied to, which is a strawman. The people that think “Just line everyone who doesn’t accept my exact interpretation of communism up against the wall” is rational praxis don't exist in any significant numbers, yet the word "tankie" is thrown around willy nilly these days.
There are plenty of ways to rationally arrive at Communism, but really the only way to get to Tankie is, as the top comment says, rejecting Western propaganda in favor of the propaganda of so-called “communists”.
This argument is that existing socialist states aren't to be trusted and are equally bad, but becoming a communist isn't just about agreeing with a nice picture of it in our heads, but to also see what communists have done in real life.
The original comment was itself a strawman, and you didn't offer any compelling argument beyond "extremists exist," which is true but not relevant. We aren't talking about outliers, but a common phenomenon, that being communists on the fediverse that uphold existing socialist states and are called "tankies" for it.