They may not get to have as many children as they would like, but that sacrifice is necessary to provide the best environment for the kid(s) they do have.

If by "the best environment" you mean affluence or emotional maturity, then I can agree with you - it's good to wait until thirty something.

Nonetheless, most people (even in US) can't give their children "the best". They don't have good careers, lots of them struggle, many are downright stupid. Yet they breed and no-one says anything, unless a child is neglected or abused.

What I am saying is that teen parenthood, though full of hardships, is just like parenthood in other far-from-ideal circumstances.

And they get to watch thousands of young girls [...]

Yep, but the poor are more likely to breed than the rich in every damn place in the world. Contrary to other disadvantaged family types, teen mothers would need support for just a couple of years, not more than 10. It would be a lot better to push a teen mom through school and maybe college, then watch her go on have multiple children and waste away in poverty. Sure, some will have additional children. But even then, you have a bigger influence on a teenager than on a grown woman who already has many children and feels stuck in poverty. It doesn't mean grown single mothers have no chance to succeed, but it's more difficult to support them.

To exacerbate the problem, media aimed at the teen demographic glamorize teen pregnancy, even going so far as to frame the drama and suffering that comes with it as cool and desirable.

If you are referring to reality shows such as "Teen Mom", I have to tell you right away, that I don't watch it. We have our Polish counterpart, but I don't watch it either. From what I read on Reddit, the American show doesn't depict reality accurately.

I did watch on Youtube stories about Polish teen mothers from foster care. In these case I'd say it's bad that a girl got pregnant. But even then, it's not really a disaster.

So, when couple like in my first paragraph see what’s going on with teens in my second, do I feel like they should stigmatize these teens. Fuck yeah, I do.

So you are one of the people who make lives of these girls harder. I read that because of harsh judgment and mocking teen mothers often drop out of school. Thanks for contributing to the poor outcomes for these families.