Well, just about everyone I know would abort the thing (and a few have) rather than deal with it. So it’s not universal. Obviously there are a few people I know that yearn to make one, so there is probably a biological thing going on.
However, most advanced western societies have a negative birth rate, so it’ll be interesting to see where this goes…
I think being at the right place in your life with the right person can have a big influence on the desire to have a baby. I was married for a number of years to a nice (and smart) guy who essentially bored me and didn’t challenge me intellectually. He enjoyed where he was in life and didn’t feel the urge to try to things, examine new ideas etc. I didn’t want kids even though he was pushing for it. (The thought of being stuck at home in my evenings was horrifying).
Now I’m remarried to someone who keeps me very interested intellectually and all of a sudden I want to have a baby. Sticking around home is no longer boring since my husband and I can have interesting conversations.
And while the sex is very emotionally intense when you want to have a baby … it runs the risk of turning into a chore when you’ve been trying for a year. (Got the thermometer to check the temperature, the pillow to tilt the pelvis, the preferred positions for conception, etc 
)
I like kids. I like having a family. Gives me something other than myself to focus upon. Gives me continuity with yesterday, today and tomorrow. And the little things are constantly interesting. Makes life much grander.
Everyone’s life is enriched when a positive parent/child thingie is going on, and the reverse is true…not everyone wants or should have kids.
It is a rush to to through getting pregnant, and I would agree about the basic primitive “have baby with woman” feeling, but in modern societies, hopefully this isn’t the reason to get pregnant.
Don’t have them unless you really want them, I say.
So, I’m waiting for grandkids.
Not all of us.
People were making babies before they knew what it was that caused babies, and before they were even people, technically speaking. Birds do it and bees do it too without knowing it’s going to make little birdlings and beelets. But if sex were all there was to it, then we wouldn’t care for babies once they arrived, they wouldn’t survive. So once we’ve got the little critters, we also have an evolved instinct to take care of them.
There was once in a faraway galaxy a species of human that didn’t have the desire to have babies. So they didn’t, and they only lasted one generation. Elsewhere, a similar species evolved that did like babies, and so we’re still here.