Human minds have a innate desire for virtue and truth, and since objectivity doesn't exist, it becomes difficult to admit that voters would end up create an alternative truth, or at least not at this scale.
I think it always came from the fact that truth doesn't really exist. Humans can really believe anything. There is no good and no evil.
In a way, nobody should have been surprised that Trump would get elected. I don't think "misinformation" really exists, it's just unsettled disagreements about what information and truth is. What happened in 2016 was an anomaly, but it was never impossible.