O.m. is partially correct. There is a 17th century term (in actual Greek) that roughly is synonymous:
Over the last fifteen years or so, commentators in Australia and abroad have coined a range of derogatory 'ocracies' to voice their disquiet at the white-anting of democracy. In 2011 Jeffrey Sachs wrote that America was being run by the 'corporatocracy', in which a small number of 'powerful corporate interest groups dominate the political agenda.' The 'military-industrial complex' heads the list, closely followed by (and linked to) big business, and the petrochemical and pharmaceutical industries. Early in 2012, British Labour MP Paul Flynn apparently coined a new word when describing what the Coalition Government had created as 'An ineptocracy of greed.' Some have said it's even worse than this; that kakistocracy, Greek for the government of a state by the worst citizens, has arrived in some places.
And Wikipedia obliges us:
A kakistocracy (/ˌkækɪsˈtɒkrəsi, -ˈstɒk-/) is a system of government that is run by the worst, least qualified, or most unscrupulous citizens. The word was coined as early as the seventeenth century. It also was used by English author Thomas Love Peacock in 1829, but gained significant use in the first decades of the twenty-first century to criticize populist governments emerging in different democracies around the world.
And an 1964 essay of Leonard E. Read on the topic of kakistocracy opens with this variation/quote:
KAKISTOCRACY is one of those words so seldom heard that
it might be taken to represent something that never
existed. It means "a government by the worst men." Lowell
gave the term an intolerant but more colorful definition,
"a government ... for the benefit of knaves at the
cost of fools." [citing Letters of James Russell Lowell, ed. Charles Eliot Norton (Vol.
II, 1893), p. 179.]
The longer quote provided in Wikipedia from the latter work (Lowell):
"What fills me with doubt and dismay is the degradation of the moral tone. Is it or is it not a result of Democracy? Is ours a 'government of the people by the people for the people,' or a Kakistocracy rather, for the benefit of knaves at the cost of fools?"
I think is very close to the initial part of the longer definition of "ineptocracy" quoted by the OP, particularly as it construed as a criticism of democracy. It's also noteworthy that it influenced American libertarian thinking (e.g. L.E. Read per the previous quote).
One book even traced the "ineptocracy" term back to Ayn Rand, but I think that's an error of attribution. It is true however that the longer definition of ineptocracy quoted by the OP ends with the "taxation as theft" idea. And Rand basically supported only voluntary taxation.