No one is saying specifically that it's because of innovation… or a lack thereof. And there lies the rub.
Industries of all sorts are littered with examples of first to market not surviving -- Beta vs. VHS, an assortment of MP3 players vs. the iPod, Adidas vs. Nike… The first to market or an existing leader either died (Beta and most MP3 players) or had to reinvent themselves (Adidas). Was bad marketing or poor innovation the problem?
In most cases, the leading products at the time are typically touted for their innovative qualities -- mostly because no one has seen anything like it before. Or they'd gotten so used to using that product it was expected that you would continue to use it. Nothing else seemed as good.
But if you look at what causes companies or specific products to fail - despite their initial success and acceptance -- it's because they failed to market in a way that reached beyond the early adopters and engaged the average user. Their product might have resonated, but their story didn't. So they became irrelevant.
As Apple and Samsung fight this next round of who stole what from whom, the real question will be who will maintain relevance when the last man is standing. The money isn't what's at stake. It's marketshare going forward. My bet's on whoever can keep creating products that are relevant and marketed in a way that makes that relevance absolutely clear. Innovation isn't restricted to product development.