The word "patriarchy" points to a very real correlation between autocratic hierarchy and sexism. There are, and there have been female dictators and semi-dictators. But it is hard to come up with an example of an autocratic government that has as high a percentage of women in the top echelons of power (say in a list of the top 100 most politically powerful people in a nation) as many democracies do. (Communist governments officially proclaimed the equality of men and women. But they did not and do not have a large percentage of women in the top echelons of power.)

In sections 52 and 53 of John Locke's 2d Treatise on Government: “Of Civil Government” (Chapter VI. Of Paternal Power), John Locke points to an interesting reason that gender equality is a bad fit for autocracy: it put two people at the head of each family, instead of one, and thereby undercuts the notion that one person needs to be at the top of society:

It may perhaps be censured as an impertinent criticism, in a discourse of this nature, to find fault with words and names, that have obtained in the world: and yet possibly it may not be amiss to offer new ones, when the old are apt to lead men into mistakes, as this of paternal power probably has done, which seems so to place the power of parents over their children wholly in the father, as if the mother had no share in it; whereas, if we consult reason or revelation, we shall find, she hath an equal title. This may give one reason to ask, whether this might not be more properly called parental power? for whatever obligation nature and the right of generation lays on children, it must certainly bind them equal to both the concurrent causes of it. And accordingly we see the positive law of God every where joins them together, without distinction, when it commands the obedience of children, “Honour thy father and thy mother,” Exod. xx. 12. “Whosoever curseth his father or his mother,” Lev. xx. 9. “Ye shall fear every man his mother and his father,” Lev. xix. 3. “Children, obey your parents,” &c. Eph. vi. 1. is the style of the Old and New Testament.  1

 Had but this one thing been well considered, without looking any deeper into the matter, it might perhaps have kept men from running into those gross mistakes, they have made, about this power of parents; which, however it might, without any great harshness, bear the name of absolute dominion, and regal authority, when under the title of paternal power it seemed appropriated to the father, would yet have sounded but oddly, and in the very name shewn the absurdity, if this supposed absolute power over children had been called parental; and thereby have discovered, that it belonged to the mother too: for it will but very ill serve the turn of those men, who contend so much for the absolute power and authority of the fatherhood, as they call it, that the mother should have any share in it; and it would have but ill supported the monarchy they contend for, when by the very name it appeared, that that fundamental authority, from whence they would derive their government of a single person only, was not placed in one, but two persons jointly. But to let this of names pass.

The image of mothers and fathers being equal leaders of a family is not even a good fit as an image for oligarchic rule: most mother-father pairs leading families jointly have dispositions that differ more than the three individuals in a triumvirate, for example. So the image of mothers and fathers leading families jointly tends to suggest the idea that it is possible for people who are different to be involved in ruling. That is at least partway toward the idea of democracy. 

I have become enamored of the idea that involving people with different dispositions and different views in making a decision is likely to result in a better decision. Believing this forces me into the awkward position of being open to the possibility that I might be wrong even in situations where I am convinced that I am right. It also leads me to hope that my words persuade when I am right and don't persuade when (unbeknownst to me) I am wrong. 

I have enough confidence in my own views that if somehow, I were magically in the position of being a benevolent dictator in a society that would tolerate a departure from democracy, it would be hard to lay down that power entirely. But one of the first things I would do would be to gather around me a set of councillors I respected and trusted who would not hesitate to tell me when they thought I was wrong. Then I would irrevocably cede constitutional authority to the council that I had appointed—and mandate a transition to democracy by the time most of those councillors would become unable to serve due to death or advanced age. 

For links to other John Locke posts, see these John Locke aggregator posts: 

• John Locke's State of Nature and State of War
• On the Achilles Heel of John Locke's Second Treatise: Slavery and Land Ownership