There's more to it than just theology. They actually seem to regard chrstianity as a religion created by and primarily applying to people of European descent. It's as if Europeans were either the 'new Israel' or the 'true Israel' (with actual Jews as evil counterfeits, G-d forbid).
I sometimes call it New Rome (could be New Greece, New Persia, New Babylon or the like). It and it's heritage is all around us. That's part of what woke some of us up to be Noachides. Chrstianity is also very popular, though, in east Asia, Africa, South America and other southern places.
Chrstianity is inherently susceptible to this radical local inculturation because of the doctrine of the incarnation. G-d not only (chas vechalilah!) becomes a man, he becomes exactly the kind of man every believer is. And every believer's country is the "new Israel."
This is not limited to Europe. Armenia has an identitarian concept of its religion that is little different from Judaism's, and Ethiopia claims its imperial house was descended from Solomon and Sheba and that they have the Ark of the Covenant!