Vandalizing HN like this is not cool.
Also you can't claim he ignored your many requests to stop, because you never made a single request to stop what can be interpreted the same way by both of you, he probably thought he followed them. Again, you were using this as manufactured justification to ban him.
One could attempt to make this same argument over virtually any ban ever. There doesn't need to be a reason in my opinion. HN has never allowed freedom to express any opinion you want. A pattern of unpopular opinions tends to result in an automatic hellban, for example.
If somehow he slips and they manage to do it, he will rephrase them next time, make them more vague and more subjective to make sure they don't. Like I saw a warning he gave someone to stop creating new accounts every couple of comments, but then in other warnings he stretched his definition farther and farther to include more comments and more time.
Anyone who sincerely wanted to follow the rules at https://news.ycombinator.com/newsguidelines.html would be behaving completely differently. Sincere misunderstandings are generally quite easy to clear up. If someone doesn't sincerely want to follow the site guidelines, they shouldn't be posting here. We're trying for a specific kind of community.
Even the worst case is easy to fix. If someone doesn't want to be banned, they're always welcome to email hn@ycombinator.com and give us reason to believe that they'll follow the rules in the future.
> When someone is routinely dropping lit matches in a dry forest, "he only started one wildfire" is obviously no defense.
He has lots and lots of comments of which only a couple that you didn't like. Absolutely nothing like "routinely dropping lit matches".