I wouldn't say that. I love my iPhone 5 and iPad Mini, but know the day will come when a new OS won't support some core feature on my device for no other reason than that Apple doesn't want to. For instance, Siri wasn't available on my old iPhone 4 and there's no way you can make me believe that wasn't for marketing reasons. There was some bullshit excuse about the 4 not having enough computing power, but for what? All of Siri's work is done on a remote server farm. You expect me to believe the 4 didn't have enough processing ability to encode a few seconds of voice into an MP3, AAC, or whatever and upload it to the server? That's ludicrous.
Some features don't make sense on older devices. I remember being bummed when iOS 4 came out and my 2nd-gen iPod Touch couldn't use multitasking, but understood that you just can't run that many simultaneous apps in 128MB of RAM. I also remember being pissed that the same iPod Touch didn't support setting the home screen's background picture. WTF? A 480x320x32bpp image takes 600KB of RAM, whether it's a picture of my kids or nothing but solid black.