There's a big difference between the 3D effect that you get through movement, and actual 3D as tried by LG (and a pretty massive flop).
Amazon's system might work a lot better than simply relying on tilting the phone, but the latter already exists and I had a number of live wallpapers that were just like Amazon's demo with the hot air balloon.
It was a nice gimmick, and one I quickly got bored of. So now I don't have it, and I am sure many people have turned off the effect on iOS 7 too.
I really think Amazon has messed up here. I expected a phone that would be dirt cheap and encourage people to sign up to the Amazon eco system (app store, TV, film, music, shopping, books etc) with the Prime account encouraging people to do more shopping and enjoy the unlimited free next day (and even Sunday) deliveries.
But Amazon thinks it can compete as if it's just a normal phone, and then all of the closed nature of Fire OS makes it incredibly unappealing. I buy loads from Amazon, but don't need an Amazon phone to continue doing so, but might have been tempted if it was so cheap I'd be mad not to get one.