What's with users of fediverse using 'Go back to reddit' as a retort to other users having different views? - Lemmy

I am seeing this pattern a lot lately, whenever a person disagrees strongly or expresses conservative/right wing views, they are told to go back to reddit. You can say ‘Don’t bring these bullshit views to the fediverse,’ or something of that sort. I am a reddit refugee myself, and part of the Reddit API exodus. Being told to go someplace I just left due to ethical reasons feels bad. So, I want to understand why it is being used as a retort. Is it really rude, or am I making a fuss out of nothing?