Because admins don't get to choose what I say in their community. They only choose if I can post in the community relay or not. I can create community events anywhere I want. Which means clients can be built to show the "real" community that is not moderated. Which also means that clients that only bring moderated events will be bashed for censorship by members. I have been there. There will be conflicts between admins and members and when those happen, it's the clients that will suffer.