@DiaSin, Remember that the XBox One is NOT being promoted as a gaming console but as an all-in-one entertainment unit. There are many, many people who will have this console and will want chat services that have nothing to do with gaming. For the majority of them, the Kinect microphone will be sufficient. Many people watch movies at loud volumes and yet the Kinect still manages to understand voice commands so I guess something is working. For these reasons headset is not being included which would only increase costs and would be something unused by many people. For those gamers who want to use a headset there will be a new one for sale or you can use an existing XBox headset with the adapter... I see nothing wrong with this approach.
@BranFlake5, Microsoft may be seen as having done things 'wrong' from the initial news of XBox One but at least they have been listening to potential customers and have made many changes to their plans, some of them quite severe. That to me can only be seen as a GOOD thing that Microsoft is doing right.
@hapkido, and how exactly would Microsoft, or any other console manufacturer make any money when customers would just go and pick up any number of USB headsets ranging from dirt cheap and rubbish up to the high end gaming headsets PC gamers use?