No, that's not fundamentalism at all. That's American Protestantism, which is already a VERY aggressive manifestation of Protestantism, which is in turn FAR more 'simplistic/extreme' than the Catholic Church, AKA the OG Christianity and therefore its fundamental form.
Those folks you mentioned are not 'strict'. They're extremists who make the all-too-common mistake of trying to make the Bible something it fundamentally is NOT. It tells us how to get to Heaven, not how the heavens work (I.E, not how science works). That's an oversimplification because I sincerely doubt you're invested enough in Christianity to make the nuances worth discussing.
The point is that you are mistaking radicals for fundamentalists. The definitions are *similar*, but very much NOT identical.