Why do Atheists object to the fact that Darwinism-Evolutionism is a pseudo-religion?

I'm totally with you on your first paragraph. You can even find those labels in the scientific literature. I don't know why they upset some people. But I don't see how you can support the rest of your premise, other than the fact that you can find fundamentalism in any view. Ever run into a fundamentalist Yankee fan? It's scary.