Fae being physically incarnate is a pretty difficult issue fof some people. Admitadly, in my personal experience, those that didn't believe in fae have fallen into 2 catagories.

Those who don't believe in the fae anyway.
Those for whom belief in Physical incarnates threatens some deeply held conviction or personal lynchpin.

I believe in physical incarnation myself. It seems no more "out there" than any other belief based on faith of some sort.