Lemmy is populated by far left Americans who were banned from Reddit for extremism. Strict ideological conformity is required or you’ll get actual death threats. Don’t go there unless you want violent communist revolution and hate discussing interesting ideas.
You probably don’t count.
Lemmy had a mix of Marxists, full on Authoritarians who claim to be communists (tankies, Maoists, Stalinilists, many Leninists), Anarchists (ie. Libertarian Socialists), and a bunch of more centrist liberals (ie. social democrats, progressives, welfare capitalists).
I’m pretty sure the person is ranting about the first three groups, in particular probably the tankies as they tend to be the least polite and most self righteous.
Nah, OP on Reddit has a bunch of posts in alt-right subs (KiA, Asmongold, JordonPeterson), their definition of far left is not going to be remotely serious.
Oh never mind then.
But yeah even a mainstream european leftist might feel out of place in certain corners of lemmy.