Most people in the industrialized world zealously believe what they are told to believe, even if it goes against what's in front of their own eyes. So making things true just by saying or writing them is not that odd.
I think the commentor was talking about Adams's support for Trump. While maybe not normal on Reddit, HN or San Francisco, it's normal enough that more than half the voters agreed with Scott Adams.
Manifesting things into reality through writing them often enough is FAR from a normal belief. Dude was a bit looney from the get go