It is hard for Brahmins to accept a person physically into our households. I state this from personal experiences.
Just like Islam and Xianity are difference from Hinduism, different communities and families have different traditional practises that they are built into. Some families cannot digest the fact that a person who consumes meat can stand in their door step. They consider that bad-luck and sin.
Is it bad, yes! It is logical and rational, perhaps not!
So the solution is, let us all keep our castes, keep our practices and remain distant friends with mutual respect. What is wrong with that?