I am guessing most did not think the darker predictions would actually come true. They just wanted to own the libs.
You guessed wrong. Unlike you, I read the thread, or at least the top layers. There were literally thousands of posts, and the tenor of the discussion was remarkably honest and thoughtful. It made for a very interesting and sober read.
Many of the posters admitted that they weren't paying enough attention, just going by quick headlines and their own family history of voting Republican. They all had different breaking points, but said that since those epiphanies they have been reading, thinking and deeply regretting the part they played in Trump's election.
Another segment voted for Trump as the maverick, non-establishment candidate, not fully realizing how disturbed he was or believing his bombast was just campaign rhetoric that would be set aside once he was in office.
Many mentioned that they voted for Trump because he wasn't Hillary Clinton. The decades-long hate campaigns against her were quite successful in making her an anti-Christ figure for reasons those people couldn't even articulate. None of them seemed to fully recognize that they had fallen prey to outright propaganda; they regretted voting for Trump, but didn't make the leap (or at least didn't confess) to the disinformation against Clinton.
Overall, there was remarkably little attempt to justify their vote for Trump. On the whole, it was of a confession, a humble admission of error, and many have vowed to work hard on Biden's behalf for the 2020 election.
The most poignant of all, however, were the younger voters who described "losing" their parent (almost always a father) to Fox News and Trumpism. Men they had respected, who had once been measured and thoughtful, had morphed into hatred, derision of others, and absolute belief in Trump. When the posters broke away from Trump, they often ended up breaking away from family as well.