The US is also still largely a transparent democracy. By soft-power do you mean the only modern country so defined by its achievements that it's culture is emulated across the world?
In the former Soviet Union and even in modern China it's fashionable and a sign of wealth to have American technology and fashion. Among many trade barriers, China artificially limits the number of American movies allowed in theaters to a couple a year because they're so popular.
Even countries with extremely friendly relations to the US take some actions to limit the pervasiveness of US culture. In the case of Japan, limiting the number of US baseball players on Japanese teams comes to mind.
It's telling that even with the magnitude of recent intel leaks there has been nothing found to indicate the US uses government funded propaganda. They don't need to.
Not to go too off my chain too much on why US culture is looked up to, but we're talking about the country that invented the car,microchip, transistor, computer, atomic weapons, GPS, and the internet.
Most of the great inventions of modern history were created in the United States, some of them by the government itself. Silicon valley continues to pump out the most valuable companies in the world at an astounding rate to this day.
So what is soft power exactly? Is it bad that a lot of countries look up to the US model of society? Is that unfair? Your claim is baseless, American culture is popular simply because the US is so successful.