I heard a rumor that Amazon wanted to offer Kafka as a managed service, couldn't get it to work they way they wanted, and then said "f--k this" and wrote something that is functionally similar.
That's wholly possible. They might have just copied the "rough design" of topics/consumers and queue-as-log, but clean-house implemented it. I wouldn't be surprised. Kafka was a pretty minimal codebase at that stage.
