Your personal life should become an affair of state when your personal life endangers others.
But the article is actually about central versus decentralized government. I lean more toward decentralized, but I have no illusions that somehow state level governments cannot themselves abuse their power.
If power were to lean in their direction, they, too, would become corrupt over time. Ohio's governor, Bob Taft, is a current, prime example.
Most of the states I have lived in have had viciously corrupt governments. Maybe even worse in some ways than the feds. They know people better, and where their "enemies" live. The local gov't controls the agencies that affect peoples' immediate lives - cops, local courts, schools, etc.
But - there's more of a chance of change at the local level, especially if the fed money is removed. Local control will only happen when it's all local money.
The difference between corrupt, authoritarian state governments and a corrupt, authoritarian federal government, is that if your state government is corrupt and authoritarian, you can still move. If the federal government is leviathan or decides your rights are only so broad, where do you go?