jeeprs wrote:Any theory as to why there is this reluctance? What factors might be behind that?
Because "religion" is now associated with superstitious and unscientific ideologies. The orthodoxy of modern thought is largely managed by materialists in mainstream science who dictate for their own benefit what best constitutes realistic thinking. They won the reality wars and now they are seated in positions of authority which come with perks such as academic positions and paid consulting. They'll naturally defend their ideology because being king of the hill has its nice perks in real life.
See, if you come out and say you believe in god, there are many intellectuals who think your research is polluted and untrustworthy.
This might only apply to intellectuals, but then there is a trickle down effect. When you have Dawkins and other aggressive atheists mocking and condemning religious people, you might feel a bit uncertain about identifying as religious, but then "being spiritual" (which means the same thing really) resolves the concern about being condemned for practicing religion.
I think science as a child of Christianity inherited the streak of intolerance from its parent. For much of Christianity's history it has actively rejected and crushed opposing worldviews. Much of science does the same thing (you're either a materialist who rejects God and anything "religious" or you're out of the club).
So, if you identify as "spiritual" then you get to have your cake and eat it too.