I guess a decent number of people here are anti-natalist.
I tend to think it'd make the world a worse place. Just because I'm miserable doesn't mean everyone else has to be. I'm happy for you if you raise a functional happy family. Feeling alone and miserable with no connection to the future is not a fun feeling.
Also, like Sherri suggested above, in a lot of countries (US included) the already-low birthrates are causing elder neglect (not enough youth to care for them), economic decline (more people taking social security etc. than paying into it), and cultural tensions from corporations demanding we ship in immigrants. Huge cause of suffering.