Really, the issue is that people in general no longer have a "script" to play to - study until 16/18, get a job, work your way up, get engaged, get married, buy/inherit a house, have three kids, care for them until 18, work a few more years and then settle down for a comfy retirement partially paid for by one's now-adult kids. Oh, and present oneself as a good Christian all the while.
Here's the thing though - not having a script is a good thing. It allows people to discover what matters to them and what humanity and society is to them. If it's something other than the current state of things - then it should've been changed a long time ago, rather than putting pressure on people to conform to an ideal that nobody wants when they're allowed to think for themselves. It's also what LGBT people have been dealing with for a long time, so you might want to ask how they deal with it, rather than asserting it's the end of society.
Single parenthood isn't the only alternative to being raised by a couple. In fact, those being the only two options is a fairly recent thing. It used to be that children were broadly brought up by communities - to the point that food would be served by whoever happened to have the kids nearby when it was served. Still happens in some places, even in the middle of huge cities - I was brought up like that. Now, for some reason (fear?), parents attempt to keep a tight leash at all times, and the only interaction with one's community a kid might get is through approved and strictly regulated extracurricular activities.