You've clearly never met a righteous sociopath. Do you really believe these people are beyond redemption?
In economic theory, Adam Smith proposes the idea that the most effective society is one in which all individuals work to achieve their own gain. In theory, this should be the most efficient way in going about life (the universe, and everything), but Smith is wrong. The most effective and productive society is one in which the desires of the individual and society are achieved simultaneously. A sociopath, especially one that's lower functioning, may not be aware of this, but a higher functioning 'path would be able to see and use this to their advantage, as well as the advantage of others around them (those they assume to be their peers).
For a higher functioning sociopath will have already found a niche in society where they are surrounded by others like themselves (corporate America, fascist society, etc), and thus will have no need to focus on petty gain.