Writing about it isn't crimethink. But it's highly undesirable for a commercial company to be associated with incest erotica. Amazon made a business decision

Writing about it isn't crimethink. But it's highly undesirable for a commercial company to be associated with incest erotica. Amazon made a business decision to stop publishing incest-erotica through its own publishing label. It did not ban other publishers from publishing that crap in its store.