I'm going to be charitable and speculate that this bias may not have been introduced deliberately; that instead it came about organically from the data the software was trained on; and that when the devs added a check whether something was "hateful" it used its own system and AI to ask itself whether it was hateful. Given the state of the more popular forums and their being pushed towards a political bias it made the AI look the same way. This wouldn't even have been noticed before the bot was banned from saying anything "hateful" because it would be emulating the normie who's been brainwashed or stifled and therefore it would behave like you'd expect an average human to.