Given her background, this is not a surprise. Nowhere in the history of the strip, for instance, have we seen or heard of anyone from either John or Elly's youth that was not related to them. The only long-term friends we've seen the occasional glimpse of were met when they were in their twenties. The same thing is happening to Mike and Liz. One by one, the oh-so-few friends they made as kids are dropping out of their lives. It seems clear that they take after their father in this. It seems obvious that he promised to keep in touch with the folks back home in Manitoba but life got in the way. April, on the other hand, seems, at least to me, to be taking after Elly. I should think that Elly richards slowly disconnected herself from her pals back in Vancouver when she was pretty much April's age because of some foolish belief that, since she'd never see them again, she didn't need to hang out with them. I'd say that, just as there are a bunch of people back in Aberdeen, Manitoba who was John would show his face more often so they can catch up with him, there are a group of people in their late fifties who live in Vancouver who occasionally think of a woman who dropped off the face of the Earth.
This comes from strange desire to put the Patterson family above all other human relationships. Since, by Elly and John's logic, there's only one right way to do things, there's no need to deal with strangers who do it wrong. The closest anyone has to a friend is a toady who laughs at a Pattersonian joke and confirms that Elly is always right. The resemblance between the Foobs and a family in the grip of an abusive tyrant animated by the unholy need to be the only influence s/he has in his/her family is not one that Lynn would welcome.