My colleague here at Ohio University Eastern is also into the psych of religion, but from a counseling background. I would agree that most succesful psychologists of religion in the US are not primarily psychologists of religion. It might even be argued that this is a good or even a necessary thing, for the specialists in a more general area apply their knowledge to the rather specific topics within the psychology of religion. Scientific people often refuse to entertain the notion that there is anything going on in our universe besides the physical. If you take any topic, there are two extremes, true and false.
Science is simply a word to describe the likelihood of an idea being true.
So scientific people simply are evaluating whether an idea makes any prediction of the future. If it doesn't matter whether you are right or not, then why bother with reason or objectivity. Your argument should not be with the scientists, the argument is with yourself. Can you recognize any difference in the strength of inference depending on the physical evidence. If you do not find any difference, then science and religion both point to Truth.