I was a "kicked out" kid when I found out just after turning 17 that I was pregnant. It was either leave the family home or get an abortion...so I left.
As for whether I'd give my own kid the boot if he/she ended up pregnant or impregnating someone, I would have to say "no" at this point, but I wouldn't raise the child for them, either.
If a youngster thinks they are responsible enough to become a parent when they are still a kid themselves, then they need to have a nice dose of reality once the baby is born and be the totally responsible party for the baby's well-being.
Too many young people today treat having a child like it's nothing more than buying a Cabbage Patch Doll, and don't have a clue what being a parent is really about. When the newness wears off and they still want to go out partying and acting like idiots, there are also too many family members willing to step in and take care of the babies instead of making the baby-momma or baby-daddy understand where their priorities NOW lay since they brought another life into this world.
Kicking a kid out because of a pregnancy does nothing but ensure that your future grandchild starts out life in a state of wretched poverty with TERRIBLE parents to begin with and NO positive role models in their lives at all. And yes, I think kids raising kids are definitely crappy parents, since they don't have a clue what life is about yet.