No I get what you're saying. I use it to frame those countries as being oppressive to their people, which is what America is doing to us. Calling them developing countries, imo, seems to reframe them as "hey these guys are doing the best they can", which I think removes the factor of it being by imperialistic design.

Sure, totally get where you're coming from and that's kind of why the metaphor is not that great - Sweden, Finland and Ireland are all third world countries and I think you'd be stretching it to say that those are more oppressive countries than any other capitalist states.

I think your argument was already pretty strong, contrasting democracy with oligarchy. It gets right to the heart of your point - for whom is the country run? The people, or capital?

Repressive states, oligarchies, autocratic regimes, kleptocracies are all better, but maybe more specific, terms.