Radical in common speech (within the US) is used to describe an outlier in behavior - zealot, would be the closest synonym for the way radical is used. Violence

Radical in common speech (within the US) is used to describe an outlier in behavior - zealot, would be the closest synonym for the way radical is used. Violence over climate change would be radical. It's an example of very uncommon behavior, not a specific quality of a radical. This slight disagreement is an issue of disparate definition. I believe the GP was simply being less than gracious in the interpretation of a comment, despite it making perfect sense how they came to their own understanding.