If it's closed source but can be self hosted, what is the business model? I think it would be hard to fight piracy in that case. If it requires connecting to a service periodically for licenses and has no free version that doesn't require that, then I believe it should be banned. I don't consider that self-hosted. If the company disappears and the served goes down, its dead. That's just running on your hardware, but not under your control. If the application is open or can be run locally without connecting to their servers and the paid portion is an add on like working as a proxy or something, then I have no real issue with that.
That said, there definitely should be a higher standard for users who are only marketing here. They should be making posts specifically for this group, not just sharing generic ads. The post should specifically state why it's useful to self-hosters and thus relevant to the group.