Whether it's right on wrong, it's not disproven by their filings, at least going back a few years. For a very long time Amazon was running at break even or thereabouts. Additionally, while the argument that Amazon had some very profitable lines of business seemed reasonable, it was never clear that Amazon could just choose the profitable ones and leave the losing ones. Loss leaders is a thing. AWS has subsequently made Amazon look amazing and they are obviously worth an ungodly sum of money, but if it weren't for AWS it would still be unclear how good of a business Amazon really is. Even ads isn't a business they get to be in for free. They couldn't just shut down Amazon's direct lines and be all ads + marketplace.