There is much more limited harm from a person wielding a knife for malicious purposes, as opposed to how quickly social media can fuel similar actions. If you genuinely believe scale doesn't matter and everything is the same as everything else, I don't know what to tell you.
I don't doubt that scale matters, it's just a bad analogy. Knives aren't comparable to social media, but if the commenter wants to play the knife analogy game then this is the conclusion.
