See what I mean, folks?
IMO this has nothing whatsoever to do with whether someone was or was not a true friend. It has to do with similar interests and viewpoints. One's non-parent friends may become parents, and if so they will again have a life more similar to your own.
This should be very easy for ERs to understand, as people frequently post here about how much they like it that they can talk here about what is most important to them-i.e. quitting gainful employment. Would this be because the other people in their lives are bad people? I don’t think so, more that similar fish school together.
Growing up in a 50s neighborhood there were mostly some older people, a couple of female housemates, and a billion parents and kids. Social life was very easy for everyone concerned.
Once I had my brother and his wife (non-parents) out to visit when our kids were small. They were polite, but they couldn't wait to get out of Dodge, and they never came back or invited us as a family to stay with them, even though I kept up a close relationship with him.
Same with ERs and their former workmates and still-working friends. Do you as an ER want to live on a working person's schedule? That isn't what I get from reading this forum- people often crow about how nice it is to not have to do things on the weekend. Well, most of your working friends will not be able to play golf on Tuesdays, or stay out late on Thursday nights.
I go out with a woman who is very much still working full speed ahead. Can she modify her schedule to accommodate mine? Not very easily, so I accommodate hers. Is she hostile that I have a much easier schedule than she does? Not that I can tell. But our time together is limited, and likely will continue to be. Naturally her networking and life story sharing will be mostly done with other working people.
Ha