TBF, I think at this stage many have figured out they likely fucked up, but after all this time the sunk-cost mentality starts setting in.

Many others were cowards right from the start. Easier/safer to think whatever the authorities tell them to think rather than actually look into it themselves. After all IF it turns out that the authorities are wrong, it isn't like these people are going to stop going with the narrative, so who needs those pesky revelations while you're trying to be the best little goy-bot possible.