Earlier quoted context omitted.
We've banned this account for repeatedly breaking the site guidelines and for using HN primarily for flamewar and ideological battle. Also, we don't allow single-purpose or agenda-driven accounts here, which it looks like this one was. But the greater infraction was how you were flaming and attacking others. Please don't create accounts to break HN's rules with. https://news.ycombinator.com/newsguidelines.html
A warning would have been welcome, because from my point of view I was interacting mainly with other single-purpose, agenda-driven accounts that flamed me incessantly. Early on in this there was even a very creepy attempt to dox me or something similar and there was no obvious reaction to that from the site. Anyway, sorry for causing you to ban the account. Edit: I created this account not to break HN rules with, but…
I don't know what you mean by "from the site", but if you mean from the site moderators, the likeliest explanation is that we didn't know about it. We don't let users attack others that way (see for example https://hn.algolia.com/?dateRange=all&page=0&prefix=false&so...) though of course I'd have to see the specific example to say anything specific.