Are you comparing earnhive to a vote bot?
No, even worse.
Why shouldnt I sell my vote?
Just like you have presidents in your country, hive have top 20 witnesses which are responsible for signing a block. Earnhive is like a corrupt president who says vote me and I will pay you. When ever you sell your vote on this big level even on country level or hive witnesses level the system is introduced to a attack vector. Other witnesses are going great job keeping the hive blockchain secure while this witness is a threat to hive ecosystem.