That being said, probably not a good idea to become responsible for other people before you've got your own life figured out.
That seems rather offensive and narrow-minded. Sometimes life has its surprises that weren't expected. Life can also throw us curveballs. One day you might feel like everything is going well but then something changes. I'm sure some of the 300 or so people at Twitter who are about to lose their jobs probably thought they had things figured out.
As a parent, I'm not sure if there's ever a "ready" point, but I definitely feel like my life (and my kids') would have been tangibly more difficult had I decided to have them a decade earlier. Parenting is hard.
You're also assuming that the original comment was about bringing a child into the world in a circumstance where it was hard to make rent, they couldn't afford to quit the job and had a horrible boss. What if these circumstances happened after having children? Not everyone can simply quit and work elsewhere.
If you're an engineer working in the bay area, you might have plenty of companies to send your resume to but that doesn't mean you're going to land on your feet. What about non-engineers? Or those who don't have the good fortune to be in an industry and location that is largely unique? I'd be interested to hear your advice for any factory workers in the Midwest where that factory closing means tough times ahead. Please, tell us how you think they should've avoided raising a family or making sure they had marketable job skills so they could land on their feet with a job of similar pay so they wouldn't have to struggle.
If everything was going great, and you suffered some disability that precludes your ability to properly support yourself (but strangely doesn't qualify you for disability benefits), you have my full sympathy. I don't think this case is very common though.
The same car crash that drenches the broke student rolls off the retired millionaire's back unnoticed.
e: Of course, some people cope better than others regardless of the situation. But to imply that having more money doesn't make coping easier is simply foolish.
Ignoring that most people live surprising and unplanned lives, even if you get your shit together, life is still full of surprises. You can lose your job, get very ill, etc even after you're good and settled in life.
Worse, we've convinced people to have kids in their late 30s and early 40s because between the levels of education you need to be competitive and the many years of working shit jobs before you get a 'real' job or at least one with a comfortable income, you'll find yourself old. Humans probably weren't designed to have kids so late in life. We're seeing a huge uptick of autism spectrum disorders and taking care of a baby at 41 is a lot tougher than a 21 year old who can weather the storms of low sleep and other issues.
The question in my mind is why has society lost its basic compassion towards having children? Reddit's most popular subs include /r/childfree and parents need to fight for basic maternity/paternity rights. In the past, the family unit was considered our more precious thing and society was built to protect it. Now soceity is built to protect markets and economies while families are just a 'fuck you if you want kids' kinda of deal.
As an older dad I think the system is ridiculous. Live to work vs work to live is a big theme in my life and the pendulum has unfortunately swung to the former long ago. Its especially obvious once you have kids.