This is a verse that I think gives a principle rather than a law. The reason is that the balance of scripture tells us that this will not always be the way things are. All you need to do is begin reading the Sermon on the Mount. Jesus tells us,
(Matthew 5:11 KJV) Blessed are ye, when men shall revile you, and persecute you, and shall say all manner of evil against you falsely, for my sake.And to show the balance you see a verse that is almost the same as Proverbs in the same section of scripture.
(Matthew 5:16 KJV) Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven.The point is that no matter how we are treated we are still to live in righteousness. We are still to seek and apply wisdom which is expressed in terms of kindness and truth in the previous verse. As Paul said,
(Romans 12:18 KJV) If it be possible, as much as lieth in you, live peaceably with all men.So? Seek eternity by being upright and living the truth. It will please God. Sometimes it will please your fellow man.