I think that the fact that the chart stopped at June 2010 makes it looks much worse than it is now. Android is newer than iOS and works on a very different environment. Support 4 devices is much easier than 4 thousand.
If you extend this chart to 2011 you will notice that the platform is more mature and most of the phones will receive ICS (my wife Galaxy S is a relatively old device and will get it).
If you extend this chart to 2011 you will notice that the platform is more mature and most of the phones will receive ICS (my wife Galaxy S is a relatively old device and will get it).