There certainly could be an issue with cartels forming that could promote inferior content by using their superior influence and hence gaming the system. Surely large amounts of steem power could be used to leverage even more value to these accounts. Even low effort posts could easily bring in more significant rewards than genuine content posted by lower value users.
RE: Steem Power design will encourage cartel formations and stop up-liking the Dollar Vigilante's posts. Reasons are all in my video :)