When Schopenhauer wrote that, the only modern "dictator" had been Napoleon, and he fashioned himself a monarch.

If Schopenhauer been born a century later he would have used a different word.

The point is that democracy is a distributed system in which it is absolutely impossible to liberate the system from stupidity. With a single leader, there is the possibility that they aren't stupid (and if they are, it's a simple enough matter to get rid of them). You can't get rid of an entire people, although when government is dysfunctional enough for long enough, the people will try to anyway in an orgy of blood. Without fail.