If someone is being ignored by 100 users, i think the other replies are generally sound here.
I think for the general question or case in the title, there might be several reasons people might be behaving antagonistically that’s not in a way that immediately or clearly warrants their content being flagged or them being suspended, but still rubbing badly against others in some way BUT also while the person still genuinely wants to participate in the community.
I think generally in communities (for product-based communities), there is sometimes some natural friction between users who absolutely love a product and others who really like some aspects but have some other major problems with it but still want to participate in the community.
The people who 110% love the product can sometimes perceive those who want to criticise aspects of the product in-depth as overly negative, even if it is genuine constructive criticism.
Having participated in and observed and moderated online communities, the most antagonism comes out from certain people (and myself) often when a product’s update and general direction sharply divides people who are fans of the product. This can pretty much rupture the community in some cases. You can see this with The Last of Us (TLOU) on reddit, with the sequel game TLOU2 having divided the fans into two very antagonistic camps with two separate sub-reddits for fans of the same series, split along their opinions/attitudes towards the second game. I’ve seen this a little bit for Sonic games too, but most personally clearly was for Auxy (a mobile music-making app).
And another case is for the game Sky: Children of the Light where people who 110% love the game often brush aside most negative feedback from being brought up, even when it is constructive, legitimate and helpful – and they even make justifications on the parts of the developers about things they don’t really know. (Again it is often when the direction of the game changed significantly to be more focused on commercialisation.) Community members repress negative & constructive feedback even when we, as students in game design class as i was a few years ago, would have given that kind of feedback to each other. And in fact, from what i noticed, often it was actually preventing bugs from being properly reported because community members just kept basically forcing each other to “encourage positivity” and cut the developers some slack when bugs came up.
I do agree that if someone is getting to a point where they’re not being constructive and their behaviour is destructive, then asking them to take a break via suspension or suspending as appropriate is warranted. Ive seen this happen before and people have come back more thoughtful and engaged.
But in the longer-term, i think the thing that actually helps the most (which i took as a lesson from observing Auxy and Sky) is having a community be open to BOTH those who 110% love a product and others who may like 70% of it but really have issues with another 30% of it. This is what i tried to model and balance on our Discourse forum when i was working at Hopscotch. When people reported bugs, often i acknowledged how frustrating it was and apologised to them for the specific inconveniences it caused, and thanked them for reporting it – before i or we fixed the bugs. This is setting expectations that it’s ok to be frustrated by the product, it’s ok to talk about it, and for bugs it says these things shouldn’t happen, and of course we appreciate people reporting them and talking about them. When people also expressed frustration for any other parts of the product similarly, i’d also try to make space for that like i did with bugs, rather than immediately jumping to the defense of the company or whatnot (which i’ve seen MANY moderators for other communities do even when they don’t work at the company). People don’t have to always 100% like your product 100% of the time to be participating in the community. Sometimes people love a product and then they grow out of it and move onto other ones, but still want to check in. (This is common for apps like Hopscotch and Auxy which are more useful for beginners in a particular discipline)
I’ve seen people before in our community and others who were very helpful informationally, then quite vocally but reasonably critical of many aspects of a product during a certain stage, return back to actively providing a helpful and informational role in the community after a core concern that had made them angry (like to a point of losing faith in the product) be addressed. I’m not saying that you have to change a product to appease every concern that everyone has. But in terms of long-term, i think that making the community a place where everyone can comfortably express dissent as well as love actually goes a long way, on this topic of users who are on borderline. Sometimes artificial enforced positivity brings out a lot more negativity and defiance from some people when they’re trying to write a critique than otherwise would happen. (How do i know? Because i also know what it’s like to be those people)