Can you explain how she "rolled her eyes and used an army of inhumans to tell synapse she won't find help in attilan."? All she said was that they weren't going to help her burn the terrigen out of the sky. They never threatened her. And this may be hard for you to comprehend, but there are those who take their religious beliefs very seriously, and they do consider terrigen sacred and it is the last of it. Taking terrigen away from them is like forcing mutants to take the cure to the x-gene.
Plus, your comparison is a fallacy as it does not adequately represent the situation. A better comparison would be if the last oil supply of the world was contaminating an environment and a company was finding a way to salvage it to keep the world stable while trying to save the animals and habitat.