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.
They weren't surpressed; he was very open about them from very early on in his career as a comic artist; they were central to his “origin story” and were woven directly into the comics. Its just, for a while, other aspects of his still-recent experience in corporate America gave him other relatable things to say that were mixed in with them, which made it easier to overlook them.
I remember reading (I think in newspaper interview) in the late 1990s his own description of how comics became his full-time focus and his deep resentment of how difficult it had been to advance in management in corporate America because he was a White man in the 1980s (!?!) was pretty central to it.