More than once I've caught myself leaning into or at least not challenging views that I strongly disagree with when talking to someone espousing them, because I felt it would not really be helpful/productive. I can see Peterson doing the same, and avoiding outright condemning the 'alt-right' in the way you desire because he might feel it would not lead to a desirable outcome.
I'm uncomfortable giving him this leeway, but I have to admit that I respect Scott enough to not write what he did without a decent degree of thought.
For myself, at least, I can't tell if this is the right approach. But at the very least I can say it's not as simple as always expressing my 'true' beliefs. That would be lazy.
As GP points out he's not so critical of his alt-right cheerleaders. Perhaps we would like it if he took some responsibility for his more regressive fans but I don't think he sees that as his problem. Maybe that's fair enough too. Maybe he just sees himself as a guy who's "speaking the truth" moreso than "a leader".
the thing makes me most uncomfortable about his attitude is what he doesn't say. demonizing 'social justice warriors' and repeating danger of politically correctness is ok, but what criticism about rising nationalism, alt-right movement? this is the elephant in the room he does not talk about, instead he is only focusing on small-minority leftist groups. don't know weather he is biased towards right, or he is trying to get-well with these group. but these are my two cents.