Having the action prominent and potentially with the default reversed would still leave it to the publisher's choice.
We can understand why they do it this way (they only need the option to exist, and can afford to apply dark patterns to it), but we don't need to excuse Amazon. Especially when they don't give a shit about what we think in the first place.
Oh I wouldn't expect Amazon to care what I think, especially with regards to digital books as at least I am not a customer.
I'm also not going to write off everything they do as evil only because of who they are though. Defaulting to disabled vs enabled would be reasonable too, though I don't know enough publishers or independent authors to know which option would be more often selected to pick a default.