society breaks down in 50 years and is utterly gone in 100 years, if no one has children
Who said anything about "no one having children"? There are some countries with (barely) negative population growth, but that is not even close to "no one having children."
people who raise children deserve credit: they are investing in the future of civilization
Meh. Civilization, in the sense of "people today, different people tomorrow, in an overall sense, is driven -- hard -- by the instinct to breed. I don't see it as something you should get "credit" for. If that's how you want to roll, fine.
What I'm talking about is the ability to exert control over your own reproductive system. You're a working person, you have a kid, likely you're no longer qualified to be a working person, because you now have a whole new set of responsibilities. If you are wealthy enough to slough those off on someone else (nannies, etc.) that's fine. Or if you're supporting a spouse who will carry that load. Otherwise, you're basically crippling your ability to be productive at work. From long nights up with baby to a whole slew of other responsibilities and necessities, some of which will extend past a decade, you will be less effective at your job, only assuming you were effective at it in the first place.
Birth control gives people a choice: They can pursue normal life without abstinence, yet slew the odds strongly in favor of not getting pregnant. It's no longer a general given that the mating process means high odds of pregnancy. Instead, we can control the when, and thereby large portions of the quality of the outcome.
Personally, I reserve giving "credit" to those people who plan the raising of children such that they are available, secure and ready for the task when they undertake it. Not when they punch a hole in the middle of their job responsibilities by pulling the "preggers" card. Furthermore, I think bringing an unwanted child into the world is downright awful.
While I am all for workplace equality, I see it as going both ways: If you do something that makes you less good at what you do than someone you could be replaced by, your job is at risk, and legitimately so in my view. Pregnancy, drug intoxication on the job (and that includes alcohol), not being where you're supposed to be when you're supposed to be, etc.