The thing is that normally there is a "filter" of sorts that prevents the terminally obnoxious/unlikable/paranoid/ridiculous from attaining any prominence in their own right. usually they would face an implacable wall of ridicule and criticism not only from those who truly want only the best and brightest to represent their "team" whatever it might be, but also from those who dont want their own image to be tarred by association
Problem these days is this "filter" has corroded away due to the fact that the people who make up its mechanism are too terrified of
a) being declared bigoted/violent/hateful for pissing off the wrong spastic troon and thus becoming fair game for every power-tripping psycho and zealous fuckwit to destroy their careers and lives
b) alienating themselves from the ratking network that creeps like Brianna Wu thrive in (i.e. her backchannels, asspat-friends with the likes of jon scalzi, cory doctorow and glenn fleishmann who themselves have perfected the whole "circlejerk/careerjerk our friends in exchange for exposure for ourselves") which they need in order to advance/survive in their industry
This is slowly fading away, but only gradually as for many journo/writer cliques the whole "push idiot politics, cherrypick troll backlash to declare all dissent a literal lynch mob" is something they have fanatically entrenched themselves in.
As much as we might wish that this is all a conspiracy to make the left look bad...unfortunately the idiocy, selfishness and nepotism of the richest fringe of the left is capable of fucking their side up far worse than any alt right op