I'm prepared to get slaughtered on this but I'm going to put it out there.
I really don't understand why friendships change so much after someone/a couple has children. I understand they have new priorities and less free time but why not make time for your friends? I don't understand how they expect to maintain friendships with absolutely no effort from their side. Most friends would be happy to do kid friendly activities, why not invite people along? People seem to just forget that there was a life before children.