But surely scientists take sides in debates over competing theories. Why would that be wrong? Merely to do research on one theory and not the other would be a subjective decision. Humans can't help being subjective to an extent.
The thing is, a scientist could deliver a purely objective discourse on nature, and then conclude it by subjectively stating that his observations have led him to conclude that nature is all that exists and there is no God, and it wouldn't raise many eyebrows. But a scientist who followed a similar objective discourse with a statement of faith ("My observations of the workings of nature have strengthened my belief in a deity") would likely become marginalized in the scientific community.
"But surely scientists take sides in debates over competing theories. Why would that be wrong? Merely to do research on one theory and not the other would be a subjective decision. Humans can't help being subjective to an extent."
To an extent, surely. But the standard is still objectivity over subjectivity.
"The thing is, a scientist could deliver a purely objective discourse on nature, and then conclude it by subjectively stating that his observations have led him to conclude that nature is all that exists and there is no God, and it wouldn't raise many eyebrows."
I think it would, if it was presented in a scientific journal for instance.
"But a scientist who followed a similar objective discourse with a statement of faith ("My observations of the workings of nature have strengthened my belief in a deity") would likely become marginalized in the scientific community."
Not if their research is not predicated on their extra-scientific beliefs. Kenneth R. Miller for instance is a well known Catholic evolutionary biologist.