My guess for withholding Android 3.x was to prevent Amazon from using Android 3.x on the original Kindle Fire. Instead, the original Fire was stuck using a modd

My guess for withholding Android 3.x was to prevent Amazon from using Android 3.x on the original Kindle Fire. Instead, the original Fire was stuck using a modded Phone OS (Android 2.3) while Android 3.x remained exclusive to tablets licensed by Google.