With all due to respect, if your family was massacred by religious zealots you'd kind of hate that religion too. You can't blame some people for not liking a religion that subjected them to cruelty, it's victim blaming.
Just look at Iran if you want a great example of a Theocratic State formed by religious zealots. No one wants that. Which is why so many flee places like that to begin with and go to the west
This is simply religious nutjobs not getting their way and then using violence and intimidating to get what they want
Can go die in a war at 18, but can't buy a gun until you're 21
Can't drink beer until you're 21, but can vote in general elections at 18
We need to just pick one and go with it, either 18 or 21