My sister had her son at 17 (she got pregnant at 16) , and she has a home and stable income. The pregnancy wasn't why she dropped out of school, because she did that long before. But she looks after her son and is doing a much better job than her mom did. Age doesn't make for much difference, it's the circumstances you're in. When she got pregnant she was homeless and jobless, and didn't have much going for her, but sure enough before the baby was born, she got herself a lovely house, an income and her child want's for nothing. So no, I don't think it's always a bad thing. She's going back to college in a few months (when her child is one) and going to get all the grades she needs.
Another example, my cousin was 13/14 when she had her first child, and she dedicated her life to raising her child, and then, when the child was 5 and in full time education, she went to college and now she's a nurse. So having a child doesn't mean you can't get a good job or education. She's about 29/30 now, and her child is healthy and at college. So yeah.
I'm almost 20 and expecting my child. ((which was something I was always told would never happen so I count this as a blessing)) and sure my situation isn't great, but, I know that when my baby is here, there wouldn't be anything that my child would need they wouldn't get. It's about being mentally prepared (which wasn't easy but you get there in the end) and getting the help and support you need. Asking for help is a bad thing!! I know that I didn't have the best upbringing, so I know in a way, the things not to do.
Then again, my mom by the time she was 21 she was expecting her 3rd child... and couldn't have been more irresponsible. I know people who are 30+ with kids, and their less prepared than "Younger Parents" so like I said, it's about preparation and circumstance.. not always age.
I have a lot of friends who have children as well, and they're all around my age or younger and there not bad parents. It just depends.