To them it is utopia but to many it is dystopia and anybody that doesn't toe their line is an oppressor that must be destroyed.
The thing is, they always end up against each other. Which is when the sensible people begin to rise up.
Purity test sorts of cults always end up collapsing in on themselves. And it always seems out of nowhere, too. But it's not. The model goes like this:
1. A small group of people position themselves as more enlightened than anyone else and start to coalesce around a niche sort of movement or cause that gives them special status among one another as unique and enlightened thinkers.
2. People come to believe in the cause or movement and/or to see it as the cool crowd, and they get on board, and as it grows it becomes sort of self perpetuating as more and more people are drawn to the gravitational pull of it's developing world view.
3. The purity tests start to arise as a way to self-identify as part of the movement and to signal "in crowd" status separated off from those outside the movement.
4. More people join the movement, but no longer because they are drawn to it, but instead because they fear being left outside or, worse, lumped in with those people (and the ideas of those people) who suspect or actively oppose the movement.
5. The movement grows too large, and the entire raison d'etre of the (originally "niche") movement (to feel special) starts to dissolve. This is the tipping point. The moment the movement hits its "mainstream" peak it paradoxically loses it's cultural cachet.
6. The purity tests move inward as a way of establishing a new niche group set apart from the mainstream group.
7. People within the mainstream movement follow along for as long as they can, which means spouting nonsense they don't believe (or at least being sure not to speak up against it) in hopes that they can pass and won't be thrown from the mainstream.
8. You now have two very different goals working against one another in the movement: One subgroup is pushing the envelope to hack the movement back down into a niche group of special people; the other subgroup is trying desperately to keep their place in what they believe has become the new mainstream.
9. You now have an ironic and unsustainable situation where the larger majority of those in the group are just faking compliance because they believe the views they are faking to be mainstream... but it only feels mainstream because of the sheer volume of people who are faking it.
10. Try as they might, there's no way for regular people to sustain this, and at some point or other they fall on the wrong side of some purity test or other; they are thrown into the wilderness, and then with nothing left to lose, they just start speaking their mind on all of it.
11. People in the movement who have been holding on for dear life start to realize that (far) more people agree with the doubts and criticisms they have been so desperately trying to self-censure, and they just start saying what they think. And with that, the whole thing collapses as a main stream movement.
12. Those who never jumped on board express cynical skepticism about the new claims by those who have left the movement who now, all of a sudden, disavow the principles they've been vocally supporting up until very recently. That cynical skepticism is well earned and deserved... but it's also true for most of these people that they never really bought into most of those ideas. They're just cowardly sorts who couldn't bring themselves to express their genuine thoughts until someone else made it safe.