Actually if you pay a little attention to Bezos, it's clear that his focus has been outer space at least since he was a college student. IMO Amazon was an opportunity that Bezos saw while Blue Origin is the fulfillment of his lifelong dream.
I've been quite dismissive of Blue Origin in the past, their pace of development seemed so sluggish compared to SpaceX, but I think that was somewhat unfair. It seems Bezos only really started pouring money into the project a few years ago though. BE-34 does seem to be behind schedule, or at least the launch vehicles are by a year or two, but that's par for the course for big rockets.
He funds blue origin with more than a billion $ every year from the sales of his own amazon stock. Without amazon filling his pockets he can't finance blue origin.
He puts more of his money in blue origin every year than the amount amazon will pay for zoox