My personal belief is to not defederate unless they are breaking rules/harassing people. It's fine to express one's opinion respectfully even if it's a different one. Otherwise, soon Fediverse will be divided into silos (kind of similar to what the recommendation algos on social media that drive people into echo chamber of followers/posts).
I read somewhere that they don't have downvotes on their instance, so they have a habit of leaving comments.