My sister used to live in Glendale, (a big Muslim community), over ten years ago. Her apt complex had mostly muslims living in it. I could never understand, at that time, why they were all so unfriendly to me. All of them.
Later, my soon to be husband, rented an apt in a different area of Glendale. Same thing, very unfriendly people.
With that said, I had friends in the past who were Indian/Muslim, and the nicest people you ever met.
Glendale is an Armenian community, not a Muslim community.
But you're right about the unfriendliness there. Very "clickish" and sometimes downright rude. Once upon a time, (in the 70's) it didn't used to be that way.