DISCLAIMER: This is not my writing (which should be evident from the fact that the writer describes Himself as a Male).

This is something my Master wrote on Fetlife, which I've posted here with His permission (please note those three words, Cheetah) because i absolutely loved it. i know it's going to be more than a bit controversial and i hope i haven't just thrown my reputation score to the wolves. :-/
It's also a break from writing erotica. Please pardon the delay, but having my brains routinely fucked out makes it hard to focus on writing. ;-) i promise i will have the next chapter of Jewel of the Harem written within a few days, and a chapter of The Commander's Concubine written within a week.

Biological fact: Males are driven, on Our most primal level, to protect Our females. On a deeper level than anything society (modern or ancient) has ever imposed upon Us, this is Our most basic, biological role within the animal species Homo Sapiens: protect the young, and the vessels that bear them.

Biological fact: Human females, like most of the primate family, are drawn to displays of aggressive behavior by Males when seeking mates. This causes some problems in modern society, when the social stigma around removing beta males from the gene pool has left those who are incapable of overcoming other Males (meaning they would not have survived to take a mate in bygone eras) in positions where they often vent their aggression against females to compensate, leading to a lot of abusive relationships.

Yet, in spite of these two facts, even women who have sworn to never allow themselves to be a victim again, seem to find that some deep, animalistic part of them squirms and writhes, moistening their panties at the thought of being seized by the neck during sex, or being held down and having their hair pulled while being fucked so hard that it hurts.
By the same token, even the most sophisticated Gentleman finds that His desires upon seeing a seductive body and a pair of "come hither" eyes will include, at some point, the notion of grabbing her forcefully, carrying her off over His shoulder the way a caveman would, and taking His pleasure of her without bothering to ask.
Of course, few of us will ever admit either of these, but let's be plain: the fact that a fetish such as BDSM exists in the first place is a testament to them. If you're unclear, take 6 hours of sexual psychology at any university on Earth.
So the question must be raised: "why does Humanity have these conflicting urges? Why do Men feel a drive to Manhandle that which We exist to protect? Why do women feel drawn to aggressive behavior from Those who exist to protect them?"
To answer, we have to put aside any and all trappings of "civilization (and of course, we have to piss off a hell of a lot of today's feminists)" and look at Humanity in exactly the way I've described: as just another animal species.
The female of this species, when seeking a mate, looks for One who is capable of fighting off predators (recall that our earliest ancestors didn't have guns or shelters and had to fight these predators with nothing but our bare hands and whatever rudimentary tools they could make). The female does this for a twofold purpose. One, it increases the chance of the offspring surviving to maturity and two, it indicates that the Male's genes are more likely to produce offspring capable of protecting the next generation in turn. This is not social Darwinism, it's actual Darwinism.
The Male, in turn, seeks to show a prospective mate that He is more capable of this protection by displaying His strength and ferocity. A Male who gets lucky enough to find a female who is being attacked by a sabre-toothed tiger has it easy: kill the tiger. However, most of Us find that there is a shortage of readily-available ravenous beasts seeking to hunt the women we desire and sportingly give us this opportunity to show off our prowess as tiger-slayers
Damned shame, right?
Fortunately, Evolution has thrown Us a bone, by making the female of this species perceptive of other signs of strength. How do We do it?
If you're paying attention, legions and legions of women out there, frustrated by a generation of emasculated "men," if one wants to call this generation such, are already answering that. All the memes calling for Us to treat them more roughly, all the millions spent on that 50 Shades drivel (which was so vanilla it made my ex-wife look like a Hot Fudge Sundae with Wasabi and Salsa), all the women who try to hide the fact that they're looking up rape porn when You're out at the bar...
Macchiavelli spelled it out for us centuries ago when he compared fortune to a woman, and let's look at his description of why he makes that comparison. "[For fortune is a woman, and it is necessary, if you wish to master her, to conquer her by force; and it can be seen that she lets herself be overcome by the bold rather than by those who proceed coldly. And therefore, like a woman, she is always a friend to the young, because they are less cautious, fiercer, and master her with greater audacity." (The Prince, ch. 25)
The Men of the Renaissance understood it, and it's simple: she freaking WANTS you to stop being so timid! She wants it to hurt a little.
Why?
This too is simple, if you think about it.
Because He who has the power to hurt, has the power to protect.
The One who can, with casual ease, leave a palm-shaped red mark on her ass that's not going away for a few days, can also, with effort, fight off that "wild-eyed 8-foot-tall maniac" Jack Burton was talking about in his CB speech. It's a primitive message, but it's a strong one, and the Human psyche is programmed to grasp it even if the conscious mind has spent too much time softened by the trappings of civilization to remember what it's reading. That message is "I'll protect you from the world, but nothing will protect you from Me. You're Mine. I'll do as I please with you, and I protect what's Mine."

The Power to Hurt is the Power to Protect