They are really commanded to avoid lusts. Marriage happens to be the means that works, and most people struggle with it so it's better for most to marry. It's in the verses you cited:
A slap in the face to Christian women who can't have children, applied literally that would imply that they can't be saved or that they are not equal spiritually through Christ. Even the slave got spiritually equal in Christ with the free, but that woman is still less.
I'd say you're taking this out of context, because the previous verse refers to Eve, who was called the mother of all living. Through motherhood the promised seed that crushed the snake came. Eve was the weaker link, but in weakness also was exalted with the power of life, which is all God's plan. He is also speaking of a contemporary lifestyle that was the only viable honorable path for Christian woman in first century AD, but this verse is loaded with so much more depth, you cannot possibly reduce this to mean a simplistic "every woman must have children at all times".
This verse describes Christian female lifestyle from a society of 2000 years ago. It isn't hard to see I think, that back then being married young and busy with your family was the only way for a woman to live and be respectable in society. As opposed to being an indolent busybody, or whoring around. Or being associated with such, simply by being a post-pubescent female, single, and mingling with people. Which was enough to give occasion for evil gossip against Christians and Christ (adversary speaking reproachfully).
The substance or spirit of this verse is, for women to live honorably. Men had more options, they could get into missionary work like Paul, traveling alone was way too dangerous for a woman. But nowadays, there are many honorable options for Christian single, divorced and widowed women who choose to stay single. Women can be single servants of God involved in charitable work.
As for these chaste unmarried, maybe divorced by an adulterous spouse, or widowed women, who are engaged in God's ministry and live honorable lives - what is there to be spoken of reproachfully about them?
I didn't see anyone here
command abstaining from marriage. Marriage is God intended for a lot of people. A person isn't more godly if they do not marry, they just have more free time and resources (not just money, I am also talking about energy, focus etc.) to allocate for God's service.