"A scoffer who is rebuked will only hate you; the wise, when rebuked, will love you. Give instruction to the wise, and they will become wiser still; teach the righteous and they will gain in learning" (Proverbs 9:8-9).
This passage reminds me of Jesus' admonition at Matthew 7:6: "Do not give what is holy to dogs; and do not throw your pearls before swine." Those who are locked in a negative mindset will respond to any attempt to challenge or correct that consciousness with more negativity. The wise, who are centered in a positive mindset, will appreciate the opportunity to learn and grow. It makes sense, therefore, to focus our energies on the wise and righteous, because it will have a positive result.