But here is the problem. People speaking for science, or as Ilion likes to say, Science!, don't accept the idea that science is subjected to a constraint.
What you get is a shell game. "Why should we be naturalists?" Because there is no scientific evidence for anything other than the physical world. "But what about the bacterial flagellum? Isn't that evidence that there is something outside the natural world?" No, you IDiot, to infer from the bacterial flagellum, or the fine tuning of the universe, to a being beyond nature is to violate the canons of scientific inquiry." It is the science defenders who seem to think that belief in anything beyond the natural is somehow a threat to their enterprise, but in fact such heresy hunting, if effective, would deprive the scientific community of some of its best practicioners, such as Francis Collins and Donald Page.
Further, for many atheists, commitment to atheism is something really important to them. I know many atheists who have ten times the zeal most Christians have for their belief. For them it isn't heaven or hell, it's progress or regression.
The scientific community has the right to define the limits of its own inquiry any way it sees fit. To then say that their domain is the complete realm of rational inquiry is to make not a scientific claim, but a philosophical one. And to reject that claim is not to be what they insist one should not be, a science denier.