This is one of those areas where liberal and leftist diverge. As the author identifies, this aspect of social justice thinking is decidedly anti-liberal.
I actually think this is one of the bigger issues we are seeing with the current debate. Historically, we have had a liberal/leftist coalition in our culture. Now that this is starting to break apart, us liberals are having to come to terms with our leftist allies not actually being liberals; while the leftists are coming to terms with us liberals not actually being leftists.
Because of how inconceivable this divide is to many people, there is a lot of strawmaning of positions. So if a leftist sees a liberal argue for the liberal position in this debate, they see it as arguing against the leftist position; and since leftist==liberal, they must be arguing for the right/conservative posisition.
Since this issue is so politized, I don't think many liberals see the left as arguing for a right/conservative posistion; but many do see them as arguing for an authoritarian posistion, which has historically been associated with the right. As a result, I think that many liberals are simply confused about what is going on since, without the liberal/left distinction, all they see is "their" side going "crazy"; when, in reality, there simply is not (and never was) the common ground that both sides thought there was.
(Obviously, any reference to "historically" refers to the recent history. One does not need to go back that far to find major examples of widely accepted leftist-authoritarians, but those are more in the history books, then in the public perception).