They are not just anti-vaxxers. They are a grab bag of conspiracy theorists, "sovereign citizens" and those who express a faith that has very little to do with what I would call mainstream Christianity. Every society has the people on the fringes. The 2 years (so far) of Covid has given all the dispirit groups a common focus so they are gathering to protest against whatever their particular issue is. I have met many pilots who can be described as nutters and they were definitely in the anti-religion camp. The author C.S. Lewis wrote a book about Satan, "The Screwtape Letters", some of you might find it interesting.