Just wondering whether this might be a more helpful and incisive way of dealing with posters who have been accused of either trolling/goading or personal attacks.
Often the problem is confined to a particular thread, which derails it completely and sometimes results in deletion of the entire thread. This can mean that the OP, who wasn't part of a bunfight and just wanted some help, loses that valuable support. If there was a 'ban-this-poster-from-this-thread' facility, the thread could carry on with the people who hadn't been reported .
It might also reduce the need for repeated warnings or whole-site bans.