Contradiction
"Amazon is happy to run others' applications, and to have its applications (with their associated content) run on Kindles, iPhones, iPads, Androids, or other form factors."
"Every Kindle Fire comes deeply integrated into Amazon's retail experience, which is why I wasn't tempted by the release of Google's Nexus 7"
If Amazon is so happy for its content to be used on any device, why would you have a problem with the N7 or any other tablet?
I'm not knocking your choice of hardware, but this seems like a contradiction to me.
What is it about the Kindle Fire's "deep integration" that's so different to using Amazon apps on A N Other tablet?
Perhaps it's different for the US though. They after all get to benefit from awesome extras like unlimited movie streaming for having a Prime account, while all we get is free delivery.