The book of Proverbs is a kind of commentary on the Torah, or, more exactly the reflection on the Torah and of the way how to execute and observe it. The Torah was never for a single person. Of course, it is suitable to every individual, who would want to build his life according to God's law. And all the same, when God gave the Torah to His people, He gave it as a law for the whole nation, and not only for individuals. He suggested to His people to relate to the Torah the entire life, not only private, but also public and State. It is not surprising that in the book of Proverbs we find quite often aphorisms relating not to private life, but to the public or of State life.
Righteousness is a whole and indivisible notion, it cannot be divided into private and public, that is why the wise man speaks about the rise and the fall of the wicked, about righteous men, whose number is multiplied, when ends the time of the wicked. One could of course say that righteousness and politics or righteousness and state activity are incompatible things, but the author of the Book of Proverbs does not see so. It is unlikely that he didn’t understand that there are not people without sin. He simply meant that righteousness quite as wickedness is just a question of choice made in a concrete situation, choice made either for the benefit of the Torah, and thus, of righteousness, or for the benefit of some other reasons, - and then it will come to forget about righteousness. If the choice is made by an influential or high-ranking person, his wickedness becomes the factor not only of his own life, but also of the life of the society.
Righteousness in such background can really get lost, become imperceptible, because public life is always more conspicuous than private life, remaining very often hidden from foreign eyes. It can even seem that wickedness triumphs, and there are already no more place for righteousness in the people, ruled by a wicked ruler. But in reality, righteousness disappears nowhere, it cannot disappear, as long as remains in the people, although ruled by a wicked, at least one righteous person. It becomes simply imperceptible, and remains imperceptible until it is again demanded. This of course cannot happen earlier than the reign of the wicked is ended, and then everything will be getting back into its place again: righteousness manifest itself to the world such as it is, and wickedness disappears, as vapors from the blow of fresh of air.