Let's see... I can think of 5 people I know who are well into adulthood without children, and a couple who only had one daughter and will never had grandchildren.
All 5 of the people with no children have dogs. One of them also has 10 cats. I would describe 2 of them as lonely people. The other 3 keep pretty busy with social stuff.
And the couple with only one daughter, who will never have any grandchildren, is lonely as well.
I also know a couple with at least a dozen grandkids, most of whom seem to be a delight. Of course, I also know a lady with a son she would probably be better off without. A lot of it is in how you raise 'em.
Show a little pity. After all, these parents are at war against the world.
I'm fond of these non-parent couples, but I did chuckle when I spent a little time with one couple who were having trouble with one of their dogs being a little snappish to the wife, a dog who had "bonded" heavily with the husband. They sounded so much like parents struggling with a moody and intractable teenager playing one parent off against the other.
There are tradeoffs. Couples without children devote a lot of attention to the other--this is a nice thing to see. Sometimes couples with kids forget how to do that.