Was Lu Xun's attitude toward traditional culture radical?

I don't think so, but he just had the attitude of "angry at his indifference" and criticized the numbness and cold-bloodedness of the Chinese people at that time. Most of his works are characterized by such feelings.

This is not a bigotry, it is just that his subjects were mostly for this reason, and he was patriotic, and he wanted to passionately express the feelings of patriotic people through his words. The society at that time was in turmoil, and he was only targeting the insensitive Chinese. This is not traditional culture.

He's more nostalgic about private schools, or at least not critical, in From Baichaotang to Sanwei Shushuya. There are also references to his reading of the Sutra of Mountains and Seas. This all shows Lu Xun's support for traditional culture. At least it is not targeted.