Both are real, to different people, in different communities.

Exactly my point. I don't know enough to make a value judgement one way or the other, simply pointing out how shocking it is when you come into contact with someone from an alternate reality to your own.

And I don't mean real as in "belief", I mean real as in actual factual reality.

So it's not an "alternate" reality (that's usually used as pejorative), it's a different situation to your own.