Thanks for the insightful posts. Every situation has its own issues and some cannot be overcome.
Divorce and single parents can be hard on kids, especially if money is tight, but if they get encouragement, love, they can be OK. It is the kids who are not wanted that really suffer badly. This can be true in a married family or a single parent family.
My parents divorced when I was 2, by bro was 5. We had a childhood with a teacher mom who worked a lot so we had lots of unsupervised time to get into trouble and she did not make much money so we had only the necessities in life. There were a lot of rough times. We only saw my dad a few times a year, and though I know he loved us, he was not mentally ready to be a father after Vietnam. He became a bigger presence as we got older. Fortunately, my mom encouraged education and my bro and I got college degrees and do fairly well in life. But we had no good model of what a healthy marriage is, even when both parents got remarried.
My bro got married young (23) and had 3 kids. I saw his wife browbeat him often and it was much worse at home. She refused to sleep in the same bed and racked up 10s of thousands on credit cards in his name that he did not know about, then filed for divorce while he was on a business trip. I think he had basically refused to confront the problems of their marriage. The kids ended up with a much less toxic home. The bro is remarried and happy and his kids are mostly undamaged, with a few cracks showing now and then.
I had a live-in relationship with a woman (my early 20s) who would quit jobs on a whim and assumed that I would cover all costs while she did whatever. We were great friends, but eventually I couldn't take the instability and fighting (I was often angry) anymore. I am now married and sometimes have trouble having healthy confrontations, but I respect and love her and she is patient with me. I try to show my kids I love them every day.