I suspect that becoming wildly cursing aggressive against any “enemy” point of view fulfills some important functions for maintaining the groupthink.

• It demotivates anyone from participating in lemmy.ml if they have an enemy view, obviously
• It creates a “conflict” that will then motivate people to step in and shut down the conversation, preventing there from being some kind of reasoned discussion on the topic that might have poked a hole in the narrative. This isn’t all that vital on lemmy.ml itself, since the mods can simply censor opposing views, but outside of lemmy.ml it becomes more important. A lot of communities will ban “divisive” topics, because of this tactic working, thus eliminating places where discussion could take place that could puncture the narrative.
• Most crucially, it works to insulate the lemmy.ml user from being able to have conversations in which they might realize holes in the narrative. If they react to certain messages by saying, “What are you talking about? There is no genocide in Xinjiang.” then a very dangerous type of conversation might ensure. If they react with, “Yeah LIBBBITY LIB LIB how much does the State Dept pay you you fucking bootlicker I GUESS YOU LOVE NAZIS fucking disgusting” then they’re a lot safer from someone having a reasoned response. Actually, the type of response they’ll get will just reinforce their overall impression that the outside world is hostile and hates their point of view. I’ve seen lemmy.ml users who seem to be genuinely confused about why people are “attacking” them when they came in with all guns blazing. In their accustomed environment, that kind of gleeful insulting hostility is rewarded and welcomed, and so when they get hostile pushback, it feels weird and like people are against them.

I think that last point is a hugely important and underappreciated feature. It’s also at work in MAGA propaganda. It’s also part of why Mormons are required to go into the outside world but interact with it within a format that will guarantee people won’t be receptive to them. Nobody on the planet is going to develop a more favorable view of the Mormons because some of them surprised them at the door of their home and talked to them about how important it is to be Mormon. The purpose of the setup is to impact the Mormons in the equation. So, also, it is with how lemmy.ml users learn to interact with non-tankies.