How or why Scott Adams went completely of the rails is perhaps something we'll sadly never understand. Was this opinions he'd always had, but suppressed, did he somehow become radicalized or was it perhaps medically induced, e.g. a stroke or something. It was incredibly sad to see him throw away his life's work and go down a path most of us at least hadn't foreseen and die having alienated his fans.
Almost everyone is reasonable, it’s the contexts that our reasons are relevant to, which are different.
I think Scott Adams' biggest problem in life (although partially what also made him entertaining), is that he'd kind of pick fights that had little upside for him and a lot of downside.