It's one of Trek's bad production decisions: the idea that if anyone out there was going to be a good guy, then naturally they'd be part of the Federation. It's fine for the Federation to be the United States Writ Large, but its existence doesn't mean that the United Kingdom, France, and Brazil wouldn't also exist.Well, it's not like they have a lot of options. Consider the powers that surround them -- the Klingon Empire, the Romulan Star Empire, the Cardassian Union, the Ferengi Alliance, the Tzenkethi Coalition, the Breen Confederacy, the Gorn Hegemony, the Tholian Assembly, the Talarian Republic. Frankly, the Federation doesn't have a lot of nice folks to make friends with -- the closest would be the Ferengi Alliance.
I can't tell --- I don't have the direct information --- but I have the sense that the Ferengi Alliance was originally-in-1987 conceived as being a sort of parody of the original Federation. The dropped hints about it being explicitly interventionist and viewing the Prime Directive as destroying opportunities for everyone involved gave me that strongest hint. So in that regard the `Humanization' of the Ferengi as it actually worked out would be also the discovery that they weren't so different to start. (Apart from not being a multi-species polity like the Federation was.)