There have also been cases where a customer violated Amazon's terms of service and lost access to all of their Kindle e-books. Amazon has all the power in this relationship. They can and do change the rules on us lowly peasants from time to time.
Note, there are indeed ways to download your books and import them into something like Calibre (and remove the DRM from the books). If you do some web searches (and/or search YouTube) you can probably figure it out.
It depends. I’m not saying I never pirate books. I’m not going to just support a publisher milking a book that should belong to the commons.
Also, some publishers have taken to raising ebook prices to as high or higher than hardback costs. For those I might buy one book by an author and pirate another. I won’t justify it other than to say I only ever bought paperbacks anyway and still remember those being like $3.99 to $6.99, so I’m not paying $18+ for an ebook novel because of publisher greed.
But if it’s an author I like, I buy their books, and support them in other ways (like with Sanderson’s Kickstarter for example).
I pirate first, and when I've really enjoyed a book I add a physical copy to the collection. I just can't get behind paying for digital shit, for the reasons enumerated in this thread here. I just wish there was more direct-to-creator payments. Music and literature are perfect mediums to give directly to the artists who create it. I don't give a fuck about whoever paid fir the digital ink. Maybe the record people get a little money.