Sure, one parent takes on two jobs, perhaps more and the other takes care of the children.
Perhaps opposite shifts could make things easier.
If someone would rather be at work than take care of their children then why have them?
As far as getting ahead goes perhaps they should establish themselves before they have kids, no need to put the cart before the horse.
No one should ahve to work more than 40 hours per week to put a roof over their family's head and food on the table. Unfortunately many people do.
It makes sense biologically to have children when you are younger. The longer you wait, the harder it will become to conceive. Some people have children because their belief system forbids birth control. Be fruitful and multiply = no birth control. Sometimes people find themselves in a family way by accident or by negligence and then decide to have the child because they choose not to abort.
My problem with your opinion isn't so much the way you choose to parent, but your judgement of others if they don't conform to your narrow interpretation of what makes a good responsible parent. I recall a wise man saying "Judge not, lest ye be judged yourself". You might be familiar with that saying...
I tend to agree with you that the parents normally do a better job raising a child than day care or a nanny. But at the same time, I am willing to accept that in specific situations, some parents may see using daycare or the services as a nanny as the best solution for their situation.