Yeah, but this community isn't about being right or wrong on a topic. It's about mod decisions.
As such, if there's a rule in place, and the user breaks it, it's kinda on them unless the rule is egregiously out of line in the first place. We're all expected to check the rules of a community before jumping in and commenting. That's just how forums work.
Once you crossed over that line, you put the issue into someone else's judgement as to whether or not to take action. It doesn't matter if you're right or wrong, or what the topic is. What matters is whether or not you broke community rules, and whether or not the mod took appropriate action.
See, that's what I think people miss. This community here isn't just a place to vent about mod actions. It also serves as a place to crowd source best practices, and as a form of "AITA" as part of that crowd sourcing.
If you come here with the expectation that the subject of the comment or post is the most important factor, you're going to be disappointed. In this case, I already said I agreed with your stance, but your stance simply doesn't matter in terms of what this community does. You could have been arguing the exact opposite stance, and it wouldn't change whether or not you broke a rule there, and thus is irrelevant to whether or not the mod action was appropriate or not.
And, hell, I even said it was over the line for a single event as far as that goes. Should have been either a direct warning that you were crossing rules, or a temporary, short ban to give a cooldown period
Any time a civility rule exists, there is only one answer to who decides what is and isn't civil discourse. The mods make that decision. They can be disagreed with, obviously. But if we as users behave in a way that makes them make a judgement call, it isn't always going to be the call we would prefer. And you did engage in behavior that can be easily interpreted as uncivil. It's our, your responsibility to check in with mods before going off if you care about the possible consequences.
You did and said what you felt was necessary. That's a good thing. Sometimes fighting the good fight has unpleasant outcomes. You walk up and punch a literal Nazi, that's a good thing but you still committed battery. So you have to accept that there may be consequences despite having the moral high ground.