We justify our actions to ourselves using a scale of moral reasoning. We broadly like to think we're taking any action for a greater good.
However, we're surprisingly open to being given a rationale for our actions.
If someone tells you you're taking an action because it supports the community, you're very likely to believe it.
If you're trying to get members to start or stop taking actions, the rationale you give them has a big impact upon their level of participation.
Here's a quick diagram:
Too often we assume the worst from members.
We focus our appeals to start/stop engaging in a behaviour at the individual level. This has several implications. We get selfish behaviour. We limit the level of commitment to the group.
For example, threatening to remove a member unless they behave is far less effective than telling the member that it's hurting the community or causing you problems.
Asking members to take an action to improve their reputation or help an individual isn't as effective as asking them to take an action because it helps the group.
If you want behaviour that helps the group, use reasoning that supports the group.