the only thing Valve can do is censor discussions and ban people for what they are saying

Except they don’t, which is the problem. Moderation of the forums is pushed off on developers, publishers and volunteers, and Valve only gets involved if they absolutely have to. It makes effective moderation of the forums dedicated to games made by small and solo devs functionally impossible, and allows for rampant abuse of the systems by publishers, such as Take Two marking negative reviews as “off-topic”.