So, yes: Android OS upgrades are not a stately situation. Apple’s pie chart doesn’t lie about that. What those stunning circles don’t tell you, though, is that OS upgrades on Android play an extremely different role than OS upgrades on iOS. Google has deliberately shifted much of Android’s core functionality away from the operating system and into standalone apps — apps that are then updated instantly and universally, numerous times a year, without any manufacturer or carrier involvement and without any direct connections to the OS itself.
J.R.Raphael nails it here. Android updates are a pain in the butt, but core-functionalities are added and updated many times a year. To me this makes sense. All of Google’s apps get updates all the time, which is much more exciting than waiting for the yearly (or twice yearly incremental update).