Following the rules gives people predictability and allows them to manage expectations in case there is an issue. Users who know the enforcement protocols of a service generally feel more confident in using a service. They also tend to want to use it more often.
If you don't know the rules, you can accidentally break them. There are no happy accidents when it comes to breaking the rules because the rules were made to keep everyone safe. This is why people don't like being identified as "rule-breakers" on services they are using. It makes them feel like rule-breaking is normal when it does not actually happen that often.
What you can and cannot do on our service is not a challenge. Do not find ways to break the rules. We do not take kindly to trolls who want to take a sophisticated social media ecosystem and taint user experiences. We believe most users will follow the rules. We have even set it up to make it harder to break them.
Knowing the rules will make it easier to identify bad actors in our ecosystem. We want users to help us identify these individuals because it is tough to follow the rules and enjoy the outcomes of rule-following if you feel like you are being harmed for following them in the first place. An ecosystem is sometimes only as good as how people follow its rules. More than that, its sometimes only good because people follow its rules.