This must be a statement of principle and not an observation. I think it is an early expression of Romans 13 rather than an explanation of how kings think. Our current leadership certainly does not embrace someone who “loves” (157) “pureness” (purity NASB) (2889) of “heart” (3820). This is about how we should treat political leaders not an expectation of their response.
In case you have not read Romans recently, chapter 13 starts off this way,
(Romans 13:1 KJV) Let every soul be subject unto the higher powers. For there is no power but of God: the powers that be are ordained of God.This is written about the Rome that would execute Paul and Peter. This is the Rome that would send Christians to the lions. Yes, that Rome. Paul told us to be subject to that government. Solomon says to be righteous and a friend of the king.
So? It may not be easy. It may not make sense, but then neither does turning the other cheek. It is still there.