This idea that I keep hearing that anarchy is somehow "natural" is absurd. Anarchy, the absence of rulers, runs directly contrary to nature. It is not the point of least resistance, a default, or a natural state of humanity. It is the result of overcoming the base and egotistical elements of human nature which would compel you to dominate, subjugate, and exploit your fellow human beings.
Nature is full of rulers. The predator rules the prey. Members of the same species vie for dominance. Animals survive at one another's expense. Rape, theft, murder, and tyranny (if you can call them those things, since nature is amoral) are commonplace in nature and part of the natural order. Even slavery is practiced by some animals.
Sure, there is cooperation in nature. But this is something grown into, an example of overcoming the baser natural defaults. Great things happen when these defaults are overcome. But they, themselves, are the exception, not the rule.
Natural is not necessarily good. We are not like non-sapient animals with little to no moral agency. We can think about the consequences of our actions, both for ourselves and others. We can do better than the natural order. And, if you look around at the things we've built which are directly contrary to what typically occurs naturally – from cell phones to sewage systems – it's clear that's what humans do. We naturally resist the natural order, go against the point of least resistance, and create new, better orders out of the chaos.
Anarchism, a society without rulers, is the apex of social order. Humans have unwittingly strived for it for thousands of years, with numerous ups and downs along the way. It is a difficult thing to strive for, as it often comes into conflict with our other instincts – our pack mentality, our desire for security, our egos, and our need for things to feel under control. And yet, anarchy is the ultimate fulfillment of who we are – sentient, sapient, autonomous individuals. Therefore, we continue to crave it, just as we crave survival in a nature which constantly strives to snuff out our existence. And, thus, we work directly contrary to nature to fulfill our own nature against the natural order.
[Note: Before someone begins quibbling about the word "nature", I am using the term here in contrast to what is "artificial". That is, I am contrasting what is created through chance with what is created through thought and intent, or something close to it. I am aware that "nature" is used many different ways. If you don't like my use of the term here, simply substitute one of your own choosing with the meaning I have expressed above.]