I'd sum up Amazon's problem this way: it (or rather, Jeff Bezos) desperately wants to be Apple with a tightly integrated ecosystem, but it doesn't really understand Apple's approach. Amazon designed the Fire phone for itself, not for actual users -- it's more interested in putting shopping links on your home screen than things you'd actually like. It also forgot that special features aren't special if they're just ooh-ah party tricks, like Dynamic Perspective; they have to be useful.
This is pretty much my feeling as well. The Fire Phone seems to have been designed by Amazon, FOR Amazon, not for the customer. All it's special features seem to be centered around tracking you and selling you stuff (from Amazon). Personally, I find all the extra cameras (supposedly used for dynamic perspective) even more creepy than the already excessive number on most phones.
If Amazon wanted to do a phone right they should have made it cheap and I mean CHEAP, as in free, along with reduced service costs. It's basically one big Amazon commercial in your pocket. I hope they pay attention to the fact that the Fire Phone failed miserably, while the Kindle Fire succeeded. I feel the Kindle Fire was done quite well, except for that god-awful carousel.