Using toasters to make toast is fine. Letting toasters vote is not. There's the line.
"How do you stop a bot?"
Well, regarding the issue on Steem, which is bots voting, the reason bots are used to vote is to manipulate the rewards mechanism profitably. Eliminating the ability to financially manipulate the rewards mechanism will end incentive to use vote bots. I have proposed a functional mechanism to do so, which I will not detail again here. I have called the mechanism the Huey Long algorithm, and if you're interested you can find it in my comments on a post by @blocktrades some months ago when they sought a plebiscite on how to fund SPS.
I have limited means, and so selectively downvote spam and abusive self votes using botnets where I can reduce the ROI of such vermin. I don't bother flagging bots that aren't used for profiteering, nor do I vote other than organically, so I don't follow any trail or use an autovoter. Votes are only valuable if they are something people do personally, IMHO. Financial value inuring to votes tends to corrupt voters, and using bots to do so is but one means of corruption.
I don't want to ban them. I want to make it valuable to be a person in society, and mechanisms that make it just as valuable to be a bot are bad policy. Guns and drugs are something people use to craft society, so keeping them from being used to financially manipulate is something I also support.
I don't want bots to be economically encouraged to dole bullets or heroin out either, for the exact same reason: doing so degrades humanity.
People are what create value using their judgment. Corrupting that judgment by bribery is therefore contrary to societal benefit.
RE: Untangling the Gordian Knot that is Steem Ethics