It's about the difference in quality of debate. Their manifold flaws notwithstanding, at least most neoreactionaries are articulate (Moldbug almost esoterically so). SJWs on the other hand feel entitled to go apeshit on you -- to hell with convincing and productive debates.

The steelmanning is due to the fact that neoreaction is a strange composite of a few very good things (originality, aesthetics, appreciation for virtue) dispersed in an extremely toxic medium of hatred, drive for dominance, and undue confidence in the rightfulness of their own ideas. (Most of neoreaction only makes sense from a sociopathic perspective). A mind that is wise and cautious in judgment sees the good along with the bad and figures out these guys can't quite be total sociopaths if you listen to them talking about what they like and strive for (and besides some of them can put up a strong case for their position), and so proceeds to attempt to filter the good ideas from the hateful drivel. A productive discussion may sometimes ensue; NRs may be quite hateful, but their natural habitat is the ivory tower rather than the sewage system that is the comments section. If you want far right low level trolling, there are better places for that.

By contrast -- I don't know what your experience was with SJWs, but this is how it was for me -- SJWs do nothing but low level trolling. They aren't going to give you anything you can conceivably desire out of the discussion (not even timely exit); they just want to fight. It's a great stretch of imagination to connect their verbal abuses to that one trait that psychologically distinguishes left from right, tenderness of heart. It's not difficult to see how they can be even worse than NRs at endearing themselves to one. The fact that they managed to exasperate Scott, who comes off as a supernaturally patient person in general, is a fact that should bear some consideration.