I always assumed it was just because nobody uses the Amazon app store.
From a consumer perspective, the Amazon app store has no real reason to exist. It's just another place to download the same apps that are already in the Play Store, only with the extra hassle of needing to sideload it and set up a separate account from the one you already use for most other things on your phone.
If Amazon is actively making the app submission process worse for developers, then that is a colossal failure on Amazon's part to understand their market position. Developers are not the ones who need Amazon in this relationship.
From a consumer perspective, the Amazon app store has no real reason to exist. It's just another place to download the same apps that are already in the Play Store, only with the extra hassle of needing to sideload it and set up a separate account from the one you already use for most other things on your phone.
If Amazon is actively making the app submission process worse for developers, then that is a colossal failure on Amazon's part to understand their market position. Developers are not the ones who need Amazon in this relationship.