To be fair Apple updates aren't exactly a dream come true. You'd have to be pretty naive if that version number under settings > general > about is more important then core apps you don't get on older devices.
People go on about will X number of iOS devices got iOS 7 on the same day. That's true and they all ran like crap aside the iPhone 4S and 5. The iPad line has laggy stuttery gestures especially 4 finger (haven't tried the iPad Air yet). The 5S is getting BSOD caused by native apps (I believe this May have been fixed with 7.0.3). The 4 is kind of laggy and lacks the visual effects. Aside from a couple bugs introduced from iOS 6 > iOS 7 I've been pretty happy with my iPhone 4S on iOS 7.
Regardless we shouldn't be surprised Google doesn't cover 100x the amount of devices. The gnex had its run, it will still get native app updates and 3rd party app updates for years to come more then likely. I don't see much (anything) that I couldn't live without in Kitkat.
I've actually been impressed with Google devices supporting updates outside that 18 months. My Xoom got it's Jelly Bean update (finally, thanks Verizon /s) 30 months after it's release.