We ended up going and meeting our neighbors - including shoveling snow of the widow nearby with my young son.

We developed nice friendships with them. Great people. We learned that in that area, most don't do the "meet the neighbors". But they do develop very loyal friendships with people, growing over a long period of time.
If we hadn't gone out of our way we may have never met them in the years we lived there. When we returned for a visit 3 years later, the widow said "I still haven't met the new people"

When we moved back to Utah, we learned later that our neighborhood had about 3 non-LDS families.
Before we ever went to church, just about every other family came and greeted us--bread etc.
None of the non-LDS families did, including one who never did. The other two we went and said hi to them.

I'm now curious to see how long we'll live here without that one family ever talking to us.

Not exactly on topic here, but it reminded me that being outgoing and meeting and greeting people is not all that common, wherever you live. Here often the first place people meet is at church, instead of at a home. No wonder people who move here and see "everyone else" being friendly feel left out. I don't see it as an "LDS being exclusive" issue. Everyone's busy, and church is a convenient way to meet people, esp if you're not the kind who goes door to door meeting people.