He is not radical but he is outspoken and does not let himself be cowed. This antagonises other outspoken people who have been able to silence a large part of their opposition by labelling them as racist, insert-whatever-identity-phobe, nazi and such. When they tried the same with Peterson by calling him a 'transphobe' their attempts spectacularly backfired in that they drew the attention of the general public to Peterson which quickly gave him a much larger following than he normally would have had.