If you are buying a smartphone with a 2 year contract you sure as hell should care about how well you will be taken care of when it comes to OS updates during that 2 year commitment.
Why so?
In the history of cell phones (not even smartphones) iOS's ability to update easily is something no other phone platform has offered. Given the millions of cell phones sold, and the fact that Android is the top platform by volume despite this "flaw", it seems that the average consumer doesn't care that their phone gets updated. If anything, the market shows that consumers are willing to trade updatability for other features such as lower upfront cost, LTE compatibility, etc.
For every user on this forum that has a non-locked Android phone they have the ability to upgrade it themselves. So who gets screwed?
People who know and care about upgrades - Can get it
People who don't know anything about Android upgrades - Get to keep the software they are comfortable with
I have never met an iPhone/iPad user who brags about what version of iOS they have. in fact I have encountered quite the opposite- people who purposefully hold onto older versions of iOS to maintain jailbreaks (like my wife's iPad running iOS 4.X).
iPhone/iPad users brag about their apps, not their OS. The fact that people clung to Windows XP for years shows that people don't really care for OS updates as long as they apps they want work.