What do you think happens if a majority of people use the services? Will you get a return and profit? No, because the voting bots power will be saturated, and the vote you get won't be worth as much. This scheme/scam only works because not everyone "plays". The way Steem was designed for people to earn votes through other people voting, does work when applied to everyone on the platform. Vote buying does not. It fails when applied to everyone engaging in that behavior.