Comment farming is the most basic Steemit strategy.. everyone is doing it.. and beside Bernie made those bots and invested on them.. so I see nothing unusual if his bots are used for his farm.. and it's not like he is using them all on himself.. he is using them to vote for other people's quality post and flag posts which are not worthy.. if you read steemit whitepaper.. it's written there for big whales to police the community..