One other thing that makes dictatorships inferior and democracy preferable over all other systems of governance is transition of power. In democracies, it's encoded in the system in such a way that everyone seeking power wants to play ball. In dictatorship, if someone wants the power, they usually take it by force, leaving a lot of bodies behind - and the very threat of that is already a force making dictators increasingly paranoid.

That said, I think every western country could use a temporary (say, 6 months) switch to dictatorship, because I worry we won't deal with this effectively otherwise. I have no idea how to ensure such a dictatorship would be temporary, though.