This is true of the "hipsters". but lets be honest, Apple hardware lasts, and unlike Android or Windows (up till 7) you needed to upgrade your hardware to run the latest versions. Apple has always let you upgrade iOS versions whatever model you might have. My 2 year old iPad is running iOS7, my 2 year old HTC Sensation XL has not had an update in over a year. In fact I moved to an iPhone partly for this reason as it is riddled with bugs. Anyone remember the Vista upgrade debacle?
I think both you and Ian2 are being a little "sweeping", in stating that all Apple users want to run the latest model. Something else to consider is that "hipsters" that upgrade like automatons, usually factor in that they lose very little money in trading their current hardware for new, nothing the Surface, WP8 or Android devices can hold claim to as their used price is very poor
I don't think one needs to be a 'hipster' to appreciate the ease of upgrade offered in Apple's walled garden. And, it would be inaccurate to sweep all users of any platform with a simplistic broad brush, right?