Look I don't know how useful or "good" is it to be extremely aggro on twitter/nitter like Roderic usually is, but he's right.
I can never really fault him for it, it's a dumb social media and there's not much point to it if you don't actually engage with people and are able to criticize what they say, especially when talking about influencial people with a platform. And yea, he's very aggro, but his original response is not really directed at JP as a person, just angry and critical at the ideas he's peddling, and for good reason.
JP's reponse is a pretty typical one for western leftists. Criticism is seen as an attack, it is always reinterpreted in an individualistic lens. Attacking someone's really dumb or dangerous idea is immediately rolled back with "woah there calm down maybe you could be civil" as if the person criticizing is being mean, rude, or violent, when often (as is the case here) that's not the case. If you're going to talk about political things and ideas like there, and someone tells you publically "This is completely wrong and dangerous what the fuck", your response shouldn't be "Why are you attacking me?". Criticism is not a conflict, it's not a fight, it's not personal, and it is extremely important and necessary.