Muslim here... specifically Indian Muslim here.
That's not always the case dude.
I went to a Anglican school, because I was the fat kid in the school I was always the school Santa Claus!!!
I have been to churches too, attended Christmas events and so forth.
When I was sick and in hospital I had some nuns who came and prayed to me.
Just coz I am a Muslim doesn't mean I would not want to hang out in a church.
Yeah I get it some Muslims would want to stay within their places of worship its their "personal" choice.
By the way if I a Muslim walked into a church in india, it would be perfectly normal, nothing out of the ordinary. Guess in USA its different.
Muslims aren't one single monolithic group, we are diverse with different cultural practices.