I just went to check and it looks like they were banned for asking somebody to kill themselves...? Feels like maybe they shouldn't be doing that, regardless of whether or not they were on their fifth account.
And the thing is Reddit doesn't go straight for the perma. A user generally has to have a history of warnings and smaller bans first.
I know this doesn't apply to all but it applies to many: I used to mod a sub that I made like 15 years ago and I have seen the worst behavior from people over the years - deranged people who feel they are the center of the world and behave in insane ways - they disappear after a small admin ban and when it's over, they'll come back even stupider and angrier. And the best, the best, the best and most predictable part is when they portray it as being banned over one thing. No, it was a banning for a pattern of being a heinous cretin.
From what we see in this very post and comments, it fits the archetype.
Yeah that's a 'go fuck yourself' type deal. If that's what OP did, then that's what I'm telling them. To go fuck themselves. (And also to stop playing the victim here)