They think that without distinguishing features, an amorphous blob, there will be nothing to divide people and so their utopia can flourish.

They point blank ignore humanity’s tendency towards natural hierarchy. Even in their homogeneous vision, people will find ways to separate and form groups and those groups will once again have animosity toward one another and the cycle will repeat.

Destruction is all they know. They can’t harness inherent strengths, easier to just tear things down.

Physical separation from these people and ejection from society of anyone who reverts back towards these beliefs is the only way forward.