Whales supported Steemit in the beginning by mining the blockchain, they own most of the Steemit coins. Essentially they are the CEO and board if comparing to a corporation. They literally have the most invested interest in seeing that steemit is a success. As steemit continues to gain in popularity, others most actively engaged and reinvest most of their Steemit to Steemit Power (i.e. Jeff Berwick of the Dollar Vigilante converting all his Steemit to Steemit Power ~$60,000), will eventually earn the title of "Whale". Hope this helps.