I still feel there are ample suggestions provided in Islam that allows honour killing to continue. That is why it is so prevalent in Islamic societies.
Then why do the Christians and other non Muslims in that region do it too?
You also forget that India was ruled by Muslims for almost 800 years. So much of the Islamic tradition would have made its way into its society. The British ruled for a mere 200 years and we can see what influence that had. So the Islamic cultural influence would have been much greater.
As much fun as it is to blame Muslims for everything on this one I do not agree with you. The murder and violence against women and girls is found in every single culture around the world. The Muslims do not have a monopoly on killing over sexual pride and honor.
I agree that shame and honour cultures clearly exist outside of Islam and definitely predate it. However, I think that Islam has helped to cement it in place such that societies that adopy Islam become increasingly shame and honour based in ways that they weren't previously.
I think the logic of shame and honour stands on its own and doesn't need any particular God to support it. Shame and honour is where the highest goal of your behaviour it to maximise what others in your family/community think of you. When your honour is upheld, you live on beyond your death in your 'name'. It's like an attempt at eternal life. Even in the West, 'I want to be remembered' can be a pretty strong driving force.
In traditional societies, a man's honour is often bound up with how he is able to protect his women. Women therefore become vulnerable elements to a man's honour. The greater the risk to a man's honour, the stronger the 'protection' becomes - essentially through the all-out control of the woman.
For strong shame and honour societies, honour is like a glass that once broken cannot be put together again. When a person's honour is gone, it is as if they are dead. So actions to protect or restore honour become more and more extreme.