People don't act this way because they are men.
Half right. They act that way because the culture has told them that because they're men, they're entitled to police what women do with their bodies, and that women aren't really human the way they are, so killing them carries approximately the same moral weight as getting rid of a malfunctioning machine.
This is seriously not an Islam-specific thing. We simply don't hear about the cases that happen every single day where women are tortured, raped, beaten, and killed by men for not conforming to the men's arbitrary standards. In our culture, we don't hide it behind a religious euphemism; we call it "domestic violence," and most people insist that it's a personal problem, rather than the inevitable, cultural result of a society that continually others and dehumanises women, and places men in the role of enforcing women's gender conformity.
When "honour killings" happen in Western society, we shrug our shoulders and call it "child abuse" or wonder what she was doing marrying that abusive loser in the first place, and asking "Why didn't she just leave?" Pointing this up as though it's specifically to do with Islam is misleading and mendacious; Islam simply provides a different sort of cover story to the standard Western narrative(s).
Incidentally, fundamentalist Christians would openly do this -- and claim it was part and parcel of their religion -- if they thought they could get away with it. They've been working hard, actually, to try to change the laws so that they can. (For a really scary time, look up "Christian discipline" and "voluntary slavery.")
I have nothing to add.