Whales upvote the lottery winners because the want them gushing from the rooftops about how amazing Steemit is and how it has changed their lives and made their dreams come true and all they had to do to make thousands of dollars was tell the world what neat person they are. You see where this is going? Who wouldn't want to get paid for being neat? It doesn't matter at all if the content on the main page is crap, there's a lot of dollar signs. People want those dollar signs. Badly. And they know they can write a better post than make-up man.