To be clear, not talking about this community, obviously 😛.
What's the point of writing down rules, if mods just do what they want? But I suppose that's the risk you take when you call someone a liar in a small community; they might be a mod.
Edit: I'm not trying to say that mods suck, they perform a useful and often thankless job. Just that it can be difficult for small communities to get a healthy number of good mods, which can become a problem.
A lot of moderated instances with vague rules like that have quite a bit of nuance. The mods usually arent jerks looking to ban everyone who doesnt agree with them, and if they are then they did you a favor good riddance. One of the issues with the classic "but mah free speech" sea lioning that occurs on reddit is it makes it hard to actually keep things moderated and civil. People get outraged and start going "the rule says that Im not allowed to be an asshole, but I was specifically being a asshat and I think if you really wanted no asshats you should make a rule about it"
Which does lead to granular rules that actually do remove nuance and discretion from enforcement.