The way I see it, there are pretty clear socio-historical reasons for the phenomenon of men abusing and hitting women and women being more or less coerced into remaining in the relationship. Men, in their role as the traditional breadwinners, established a situation of total dependence of the female on the male, the female needed the male to bring the resources, the kids needed a father, etc, etc. A lot of that has become more or less a thing of the past in modern industrial societies, though of course the phenomenon remains perhaps because of the residual sense of shame from those days.
Perhaps most importantly in the modern setting, a good deal of the reasons are probably the victim's own psychological issues. Of course, the abuser is more fucked up by the pure fact of being an abuser (in other words, that's a given). What seems to be less easy for people to accept is the fact that if many of those other social, cultural, or economic issues are no longer very important (i.e. divorce/separation is acceptable, both partners have a means of making income, etc.) and an individual is still for some reason accepting of a physically abusive relation (whether male or female), then it's obvious that the victim's just got some fucked up issues of their own. It's still tragic, but quite distinct than from a situation in which the dependence and abuse are socially institutionalized (think Taliban-styled rules for women).
Now, I'm not a psychologist so I really don't know anything and this is just my view of the subject, but what both men and women (in the setting that I just described, typical industrial society) who are physically abused by their partners gotta do is wake the **** up and dump the *****/bastard or seek professional help. I know at least I could never be in a situation where my partner beats me for the simple reason that, barring a clear escape route, (and I know this is going to sound horrible, and it is, but it's the truth) I would hit back.
On another note, the claim the "men are second-class citizens" is frankly kind of pathetic and laughable.
