It's also absurd because the teachings of Christ are so unequivocable in terms of showing mercy and brotherhood to all people, period, with no exclusions, that for someone to claim their Christian faith has lead them to discriminate, it just shows how little they understand their own faith.
I realized a long time ago - back even when I still considered myself Catholic - that for most people, religion is just their gang affiliation. a tribal identifier. They've mindlessly picked a side, - or more likely were brought up in it - and they're sticking to it.
If you try to take them at their word, that they have sincere religious beliefs then you just end up confused how someone could refuse to do something for someone based on who that person is, then on Sunday go listen to their priest say "when you do this for the least of my brothers, you do it for me."