What are the similarities between orphans and unripe strawberries?
None of them get picked.
Listen here, smarty pants. The joke plays on the double meaning of "picked." Strawberries are harvested, and orphans, well, they hope to get adopted. The punchline is dark because it points out that orphans are often not chosen, just like those sour, unripe strawberries nobody wants. You probably have never been "picked" for a team in your life.