There are some teams where it's normal to work longer hours - mostly in AWS. Usually it's the case that a few people on the team have very high expectations for themselves, and that sort of forces everyone else to meet those same standards. I think that's actually not a bad thing - some people just love to work, and they end up producing a lot of really high quality software. But if you don't feel the same way, you can just transfer to a different team! I haven't heard of a manager asking someone to put in extra hours except when there are extenuating circumstances.
Now, don't get me wrong, as an employee you definitely get the impression that Amazon doesn't care that much about you. It's not really a fun place to work or anything like that. But some of these articles make it sound like everyone who works for Amazon is begin taken advantage of, and that simply isn't true.