guys saying that apple is not supporting 2011 machines because it was a planned obsolescence move is overthinking.
Apple simply has limited resources, believe it or not, and they'd rather expound the extra energy required to support the older machines to better support the later machines.
simple as that. sure, they can hire more people, but Id rather hire more engineers to make the next OS better. who wouldnt?
Apple knows businesses with old Macs who must run Windows will see they are no longer officially supported and will be 'forced' to upgrade, or the users of older Macs will run to their boss and say they need a new Mac. It's just Apple doing what Apple do very well.