I disagree with this, at least with what I have seen and been told, but if truly one is banned immediately with a few errors that could be guided and corrected without a warning, then that is cruel. I can't however side with anyone outrightly as I've seen a whole lot of users with powers getting intoxicated, nonetheless, if such issues are raised, I think that such an account could be reopened.
Many users have been here even after doing repeated violations like plagiarism multiple times. The community sees them negatively while many members were banned right after one report. You will find a lot of cases where some people had the benefit of the doubt while others didn't get a single chance. I don't want to mention any names but if you search for such things, you will find them for sure. Yeah, I have seen that Admin Cyrus opened a 2nd chance thread for the users who was banned from this forum. But, I believe most of the banned users already build their 2nd account in the mean time.