Regardless of the origin, it's now undoubtedly a Trump thing after he went on national television to whinge about the so-called "violent alt-left". Anyone who continued to use "alt-left" after that (as pplswar did) should be ashamed

Why? I'm not challenging, I'm just curious why you think so.

As a general rule I think anyone who thinks Corbyn is too far left and has to start red baiting about mild socdem policies doesn't belong on the left but that's just me.

He hates Jeremy Corbyn? Isn't that every democratic socialist's wet dream? He even afaik talks about "democratizing industry" something Sanders doesn't even talk about (or afaik he doesn't) so I'm kinda shocked by that. But I'll trudge through his material and see what's up. He's a pretty condescending douche though.

Even among revolutionary socialists these "types" don't exist outside of tiny online circles and the deranged fantasies of Breitbart readers

I figured revolutionary socialists want to form the "dictatorship of the proletariat" that will attack everyone who disagrees like what happened in the USSR. Regardless, afaik the DSA are "evolutionary" democratic socialists so trying to lump them together is kinda silly.