IMHO this is only an issue for the early days because there are only few prominent individuals around. Once people have to pick from a larger set of prominent authors, then things will even out more. Remember, you can only upvote up to 20 comments in 24h with your full Steem power. If people run bots and end up voting for more posts than they won't make as much and can only jump on some of the bandwagons.