If there ever was an inappropriately named action, I think "hono(u)r killing" is it. I think the press should start referring to them as "misogyny murders" or something of the like. Honor killing sounds too sterile for my taste, and it kind of masks the brutality and inhumanity of the act. It sounds almost like hara kiri, or some other traditional form of killing oneself for honor. Words matter.
I actually agree with your position and think calling these events "honor killings" is just ridiculous. But that said, I think there's a not insignificant portion of the population - in the US at least - that likes to serve as the PC police and would respond to a change like this with claims of Islamophobia and cultural insensitivity. I think that's why, for example, you don't see this more in the mainstream media. I think it's important to remember that not all Muslims are terrorists, obviously, but Islam has a huge PR problem and fails to address the elephant in the room (namely, that a not-insignificant number of its adherents worldwide believe some pretty crazy things). In the US, this is parried with "but we don't believe that!" by many American Muslims, which I don't necessarily doubt. But it's hard to reconcile that with the many fundamental problems Islam presents to the traditional idea of a liberal (liberal in the classical sense), Western democracy. Rather than poke at the beehive, we in the US seem to prefer a more "leave it alone and maybe it'll go away" approach - or at least that's my interpretation of the situation.