The reason why people who so vehemently defend these “vaccines” are because, in part, they are afraid, but mainly because they now have serious doubts that they made the right choice. And they’re the type of person who can’t stand to be wrong. If everyone gets the vaccine there is no one left to tell them “told you so”. They need constant reassurance from themselves and others that getting these “vaccines” was the smart thing to do.
You are talking about “herd mentality” (as opposed to herd immunity).
M. Twain said “It’s easier to fool a person than it is to convince them that they’ve been fooled.