It's called DTM..."Doing too much." I see this in the military a lot. People changing stuff just because they can just to get promoted. When you run a division at Google you want your iteration of Android to be better than your predecessors version. The people in charge are signing off on this stuff. I'm sure they have sections of people that don't want to change some aspects of Android because it's perfect. But their boss or bosses disagree. If they didn't make changes, that section writing the code for Android would be rendered obsolete in my opinion. You don't want to code yourself out of a job I suppose because certain aspects of the OS doesn't need to change. Just a thought.
I hate using two fingers for the pull down settings. I know it was changed from one to two fingers during implementation of Lollipop. It was perfect having to use only one finger to reach up and access Wi-Fi, mobile data, GPS, etc.
I'm surprised the carriers signed off on these changes. Sprint/HTC do a phenomenal job of pushing out the updates. I know a carrier can request for icons to be changed. But Sprint is probably at a point of trying to get this stuff out quickly to the masses. And Google is exercising more control over Android to where certain things won't be changed.