Two parts of my response here, going to address the bit from the end first.
It's not inappropriate to assign some blame to the community, but key to this is understanding that you're going to have shitty people in any community, and removing the trouble those shitty people cause is the core rationale for moderators in the first place. You can put some blame on the bad members of the community, but if there's a consistent pattern of shitty people causing problems that aren't cleaned up and learned from, that's a moderation failure on top of shitty community members. And trying to assign the host of the blame to the inevitable shitty folks that moderators exist to deal with in the first place feels like an attempt to shift blame off of where it belongs.
To some of that, but more the first part, I want to say that I'm very much reminded of a twitter thread from the summer about a bartender kicking a nazi out of a bar:
What you're describing is the situation that happens when you fail to purge the bar of nazis and let the one solo nazi invite all his nazi buddies. Particularly if you have bartenders who want to shut down kicking out nazis because "hey, they're being quiet and keeping to themselves, what's the problem?"
Now there's too many of them around, and if you try to do anything to any of them you have A Problem. That sucks, but the root of the problem comes from the failure to give them the boot before they were able to establish critical mass. The only way to solve the problem once you've reached that stage is going to cause strife, and that sucks, but it's the only way to resolve it without just shrugging and saying "well, I guess we're just a nazi bar now, what are you gonna do?"
