Why do none of the 2014 flagship devices feature always listening voice control?

Correct me if I'm wrong but from the Snapdragon 800 forward, does it not contain a chipset (forgive me if my terminology is wrong) that allows for always listening voice control like the Moto X? My question is why does it seems like this year's flagship devices are avoiding using this technology if it comes on board the processor. Can really just be about patents? Any one care to shed some light?