[R]apists don’t rape because they’re somehow evil or perverted or in any way particularly different from than the average man in the street: rapists rape because they can. Rapists rape because they know the odds are stacked in their favour, because they know the chances are they’ll get away with it. (Emphasis added by Libby)
Libby claims that Elliot is saying that all men are rapists-in-the-closet -- awaiting only the right opportunity. This, to me, is a misreading so egregious one wonders if it is willful.
The italicized portion of Elliot's quote references the empirically true claim that rapists are not demographically different from the population at large. In our heads, we have a vision of the rapist as this sort of sociopathic, damaged person with wild eyes and unkempt hair. But that isn't the case. The fact is there is little distinguishing him from the average person on the street (other than, of course, that he's a rapist). This is the case with most other "moral monsters" -- the banality of evil, so to speak. This doesn't mean that most men secretly harbor a desire to rape. What it does mean is that those men who do rape do so not because they scarred, diseased, or otherwise marked off from the general population in any noticeable way. The explanation for their conduct has to come from elsewhere.
This leads to Elliot's bigger point. The advantage of reframing the image of the rapist into one of this deviant soul is that it absolves the community of any responsibility for creating what is sometimes called by feminists "rape culture". Instead, under this view, rapists rape because they are pure evildoers so committed to malice that they will overcome society's strongest taboos and proscriptions to satisfy their depravity.
What Elliot is arguing, though, is that many rapists lack the sense that they are doing anything wrong in the first place. They think that the dominant sexual ethos of our society in fact sanctions their behavior (compare my post on Jewish extremist violence from earlier today) -- and this belief, of course, runs stronger when we remember that most rapes are not of the archetypical "stranger in a dark alley" variety. Armed with a belief that "no means yes" or pushing away is just playing "hard to get", they think that they are engaging in normal, uncontroversial social action. They might recognize the existence of some technical or formal bar against rape, but probably don't conceive of themselves as violating it. And in terms of social stigma, they are quite confident that nobody will stand in their way. They see themselves, at worst, as ordinary men in extraordinary situations (if they even see themselves as wrongdoers at all).
None of this implies most men think this way. That isn't the problem. The problem is that the minority of men who do think this way are not being informed that their behavior is intolerable. Rather, the message (e.g., from the rape jokes that are Elliot's target) is that they're a hilarious, endearing embodiment of mainstream masculinity.