That's how I understand it as well, but the difference is, that the wife and husband have a dependancy on each other, as well as leverage. On Steem, most people are anonymous and this just makes it so that the urge to be egoistic in the voting behaviour is increased. I could see a difference with communities, as they are probably smaller and more like a big family. And if you're sick of a community/SMT, you can always join another. On Steem, it's one main currency or sell for bitcoin/altcoins, which sadly too many people did.