Adopting a child could help young couples that are unable to have children of their own, and would give the adopted child a [hopefully] good home.
I do not see any reason why adoption couldn't be an option to young couples; it is benefitial to themselves and the child as well.
Young couples should consider adoption because not only does it help them build a family, it helps the child have a place to call home while also contributing to our earth because we are starting to have an over population problem. Overall it would be a great thing to do for everyone.
Personally, I see no reason why the young couples shouldn't at the very least consider adoption as part of the way. If they're not willing to have a baby of their own, but want to raise a family, I see adoption as a perfectly valid way for them to start a family.