Amazon will never accept BTC a payment because Amazon dont live or do business in their own world but do in countries, so there are many countries that do not allow btc so they cant accept, Whole story is BS.
It could be one reason also why amazon don't accept btc as a payment for this time is just because of bitcoin price stability in the market. Although we can't deny this, but also any possibilities will come that amazon company leaders will change their mind and they will take this new kind of currency. Not only amazon declined btc at this time, but also of some largest companies worldwide.