I'm guessing that removal of the hardware for the home button saves a lot of production cost. Over a few hundred million units a year, that can add up fast. That said, I do think there'd be more to the rumor for that change to be successful. I can see the TouchID system being integrated with force touch to avoid the accidental triggering of the home button that would inevitably be on every screen. This is a bigger change to iPhone that it appears, so skepticism is warranted.