To paraphrase Churchill (since I can't remember the exact quote): 'Democracy may be a terrible form of government but it is also the best we have...' or something like that. I also have some passing familiarity with the Hoppe quote you offer. I am always leery of 'must' and 'always' statements in a political discussion. Whenever these absolute terms are used, a single counter-example renders them a fallacy.
George Washington, for example, refutes the "Democracy of any type only assures the most opportunistic, ruthless and skilled demogogues..." statement. The ascendance of this American Cincinnatus belies the truth of Hoppe's argument (and yours).
Todays most productive individuals and corporations are increasingly international and with the use of technology are less tied to any one location or government than in the past
And government is busy keeping trying to keep up with them with ever expanding centralizing bureaucracies and nascent world government. A world democracy can only result in a Chinese/Indian coalition government that would immeadiately begin redistributing the wealth of the West. This Jacobin worship of democracy is going to come back and bite us hard.
Democracies don't HAVE to end in failure.
There are no success stories in the history of mass democracy. The only democracies that were even moderately successfully were small, isolated communities. This is why every political mind prior to Locke (Even Hobbes was a royalist) despised democracy as I do.