Even if your first sentence was true, I don't think it would explain why content with extreme views dominates. Perhaps because it causes more emotion, and the algorithms senses that emotions is what people crave.

As a counterpoint to yours, Aristotle was famous for his golden middle principle. That in vast majority of matters(notable exceptions: murder, theft, adultery) you can only achieve happiness if you do and experience everything in moderation. Don't ignore your desires, but also don't submit to them completely.