I'm not preaching tolerance here, but the more you understand your opponent the more you approach the inevitable conclusion: people are creatures of convenience, rarely going out of their own way for the sake of concepts like good or evil. If you want to change the way people act, the only way to really do it is to change what is convenient for them. Or to take certain conveniences away.
I don't go on 4chan anymore (or any social media outside HN [1]) and have mellowed out but it gave me the courage to call BS from either "side".
My theory is that 4chan hasn't become more extreme in the last 10 years. It's that "judgment-zones" like twitter and reddit have caused everyone else to become softer.
[1]: I'm serious, I didn't know about any stuff happening in the capitol until I saw it on HN.
Hate when that happens..