If you don't care about showing off then you won't publish anything. People who are actually altruistic won't tell you about their altruism.
This isn't cynicism. The hunger for respect, admiration and recognition is not a bad thing. But it is necessary for people to understand what motivates them. And it is necessary for us to construct a society in which respect is earned by performing actions that are broadly beneficial to that society (as far as we can estimate, anyway).
Today, anyone can broadcast. But that doesn't mean that everyone should broadcast. The old gatekepers weren't perfect but they served a necessary purpose. Who are the new gatekeepers?