Most of us know this member for trolling and posting negative comments but that is a part of forum, and I don't want bitcointalk to become eco chamber without any criticism.
Ditto. Let's not make this place more like kiwifarms guys.
Now...
If you see someone who constantly disagrees with what you are saying, the only thing possible is to ignore them (and preventing them from posting in certain boards apparently). You are unlikely to feel any satisfied with the feeling of getting him banned, if his posts are already bothering you.