I suppose it partly depends on how you define care. I don't believe an older couple is more capable of providing love for their child, but I do think a teenage couple are less likely to be able to provide financially to the same degree for their child.
Most teens are either in college or low-paying jobs, and almost all will still be relying on their own parents. There's no way they can provide the same opportunities in life that an older couple with full-time jobs, maternity pay and so on would be able to.
Does that damage a child? It doesn't have to. Thousands of children are born into low-income families all the time, it obviously doesn't kill them. And accidents happen - it's not always a choice for a young couple to have a child so early, although you could argue it's sometimes a choice through not choosing to use preventative measures.
But personally, I feel it's irresponsible to actively plan for a child when you can't support it. There are teen girls out there who are so desperate for a baby, but half of them have no real idea about what a baby involves beyond cuddles and dressing it up, and they don't seem to think beyond when it's a baby - a child is for life, you're supporting that little person for the next eighteen years, probably more. Why would you choose to start down that route if you can't even afford to look after yourself?