here is my simple explanation....
Steemit WItness and Nodes Mine the steem....They keep a small portion as incentive to be nodes/witnesses.....but most newly mined steem goes to the peopel with most upvotes from peopel with highest steempower! If you have $0 steempower your upvotes will be worth $0 but if you have lets say $1 million dollars in Steempower your upvotes will become as much as $5 $10 at a time! This whole atmosphere is