This definitely seems like a bad move, and not very customer-centric. It reminds me of when they disabled the download of any mobile browser alternatives in the 2nd-Generation Kindle Fire in order to push their Silk browser (which itself was terrible nearly to the point of being unusable). This is not to say that Amazon Instant Video is not a great service. It's pretty awesome IMO. But forcing people who want alternatives to seek them out elsewhere will just inconvenience them and drive them away from amazon.com.