Earlier quoted context omitted.
Like pg notes in his essay, there's a good chance that there are members of Group B who are parents but you don't notice because they're not talking about their kids all the time.
Eh? I said that all of Group B are parents in my explanation.
I mean, look, it's possible your world is populated by a discernable "Group B" who "only" talk about kids and "never" hang out after work. But that's not a representative sample. Most of us parents have both lives and kids, and express both in our public lives.
I think if you look harder at your B subjects, you'd probably find that they do the same thing. I bet they talk about their new Teslas, and kitchen renovations, and vacations, and other stuff that you'd be presumptively interested in even as a single person. But because those are "family" activities I'm guessing you're lumping them in with the "kids" bucket and... maybe just refusing to engage a little?
Again, it doesn't make you a bad person to hate kids. But if you do, at least recognize that it is you that is doing the isolation here. Parents are more interesting than you might think.