The issue, as i see it, is the math department at ut throws a staff Christmas party. 74% of the staff is Christian and celebrates Christmas. The Christian attitude, as demonstrated in this thread, is screw the 26%, let them assimilate.
Why not just have a holiday party and make 100% of the staff feel welcome? The problem with the alternative is that you're likely to never know that Haji the Hindu didn't feel welcome at that school sponsored party. Would your life be enriched by including more people, cultures and experiences? I think so.
My opinion changes completely if the party is private and not school sponsored.