I don't know what needs to be explained. Apple believes the value of increasing the battery life beyond the typical work/school day + commute is less than the t

I don't know what needs to be explained. Apple believes the value of increasing the battery life beyond the typical work/school day + commute is less than the the value of having a device that is much easier to hold and carry + costs saved by not putting in twice as much batteries and paying for a thicker enclosure.