Because he is taking more than $10 000 from the rewards pool each and every day. That money is meant for everyone - there are thousands of content creators on Steem - 6% can't go to just one person. On top of that, when he was called out for this behaviour, he started a war and attacked anyone who had the nerve to discuss the topic. The guy is a piece of shit - plain and simple.
RE: SteemLegion: Help take down Haejin without fear of reprisal [Anon account creation and delegation tutorial]