Fundamentalism is not restricted to religions. Anyone that deals in absolutes is a fundamentalist. If they say:
“You are either for us or against us”
… they are fundamentalists.
Such black and white, on or off absolutes are the domain of fundamentalist thinking… in their world there are no grays, no part way, there is only the whole or none.
One would think “open-minded” atheists and other liberal groups would not be fundamentalists. Yet, when they have groups they develop a mindset not unlike fundamentalists.
If I say I am neutral about an issue, that is exactly what it means. It means I neither support it nor do I oppose it.
Nevertheless, when I tell liberal minded folk, and other atheists, which I am one, that I do not care to become involved in, or am neutral about LGBT issues… the grief I receive is horrendous. I have been labeled so many names and profaned in numerous ways. Yet, I remain neutral… and apart from any group.
Please do not tell me you are not a fundamentalist, that you are “open-minded”, unless you really are.