Dieter Bohn, writing for The Verge on the Kindle Fire’s redirecting of Android Market requests to Amazon’s Appstore:
The Fire does run Android apps, and Amazon makes it easy by giving it direct access to its own Amazon App Store as well as allowing sideloading of apps from your computer. However, installing apps directly from the main Android Market is verboten unless you go through the process of rooting your Kindle Fire to install it.
Those are the basics, but one thing you may not have realized is that Amazon has taken it a step further: redirecting all requests that would normally go to market.android.com and redirecting them to its own App Store app. The process happens via a file hidden away on the Fire called MarketIntentProxy.apk and it’s designed to help Amazon determine which app you’re trying to find and give you the option to download it from Amazon instead of Google.
Like I said, Google can’t be happy about this. Make no mistake, the Kindle Fire is unquestionably Amazon’s. That it runs Android is true in name only because there’s nothing even remotely Google-y about the device, just how Amazon planned it.
This makes Google look like the girl who got dumped after the guy used her to, well, fuck her, and then leave.