That’s a great thought. I’d also say that you’re not telling someone they can’t say something at all, they just cannot say it here and in the way it’s being perceived.
I mentally liken an online community to real-life relationships. People earn trust with you over time and can eventually be great friends if you share similar core values. But consistent outbursts of aggression or attacks will immediately cause me to put up boundaries with that person and eventually not have very close relationship with them because they haven’t respected me as a person. However I can still choose to be respectful toward them, just with firm boundaries.
It’s so easy to forget there’s a person on the other side of the avatar online, especially when things get heated. However I personally think it’s imperative as community leaders to remember this. Set boundaries, be clear on expectations, enforce limits, but remember these are also real people, too.