I think the point is that if one side is correct and the other side is incorrect (regardless of which side that is) then someone with that point of view cannot possibly be centralist.

To be centralist you would have to conceive the both sides have a point. Centralists like to claim that they listen to both sides and then make an opinion on who to support, but they don’t, they just stick around in the middle. They never actually commit to one side or the other, because if they did that they wouldn’t be centralist anymore and they wouldn’t be able to be on their high horse.