It makes sense to discourage spam, porn, personal attacks. They're a distraction and a deterrent from participating in a community.
However, you should also discourage boring behaviour.
Boring, of course, is subjective. However, it's documented that certain behaviours discourage people from participating in the group. Forsyth cites these as:
- Tediousness. Communicating in a boring manner. e.g. too much detail, posting too long posts when most are short (or the classic TL:DR)
- Lack of disclosure. Not adding any new subjective or objective information.
- Egocentrism. Overtly or covetly promoting oneself amongst the group. Complaining about one's own problems.
- Low affectivity. Not expressing any emotions or opinions on an issue.
- Seriousness. Remaining too serious about every topic.
- Self-preoccupation. Lacking interest in other people e.g. failing to ask questions.
- Banality. Talking about irrelevant matters.
It's not just members that exhibit boring behaviour, it's community managers too (especially branded community managers).
When organizations participate in their own communities, they often fall victim to these mistakes. They often don't sound geniune. They're often too boring.
A little self-awareness goes a long way.