The fault in the present politics seems abundantly clear, but perhaps no one thinks that they would get any richer from making the point. Democracy in Athens was frequently the means of tyranny; the point was that the moderating aristocracy (Aeropagus, etc.) could be bypassed, if a single person could command the demos. The mechanism of present power is the media machine, which somehow has convinced people that they personally have an instinctive, unlearned insight and power vis a vis the national politics. Because they watch television. And so the central authority predominates, and when one person commands a predominant central authority, this is, by its terms. monarchy (you can have elective, or even legislative monarchies).
Second, the king always wants to go to war. Look at UK constitutional history -- constant assembling of parliaments to get money for foreign wars, ships money, etc. Traditionally, this is counterbalanced by forms of collective authority distinct from the nation as a whole -- the Estates, the churches, the federated states, etc. The point of the latter being that it's much better to live peaceably and happily than go off to war to gratify the ego of a king. So, in this natural balance, the wars ideally were taken up only where the people in the states/Estates/churches could be convinced that it was absolutely necessary for the country. In a monarchy in the context of a centralized state, these subordinated forms of group identity within the state matter less. Each citizen stares into the center by using the glowing machines on the wall or in their hand. Ergo, war is the order of the day.