You're broadening the scope of the issue much further than the episode did. The question at stake was never, "Should we demand that the Vissians, as a culture, change their treatment of the cogenitors?" The
Enterprise never had the power to do that, and was not asked to.
The question was "Should we grant this
one individual, who no longer wishes to live as a cogenitor -- whom we have witnessed for ourselves is systematically unpersonned and treated like an object in that role -- asylum?"
Now, I could have reluctantly respected Archer's choice if he had said, "Look, Trip, my hands were tied. These guys wanted the cogenitor back, and there was no way we were going to be able to stop them." Which would have been true; the
Enterprise could never have beaten the Vissians in combat. But he did not say that, and the situation wasn't framed that way, anyhow -- the Vissian captain never made that kind of threat.
Instead, Archer lashes out at Trip, blaming him for the cogenitor's suicide, as if Trip showing them the limits of their life was somehow worse than the Vissians imposing those limits in the first place, and worse than Archer allowing them to be forced back into their not-even-gilded cage. He explicitly gives Trip hell for meeting someone whose culture has enslaved them, and treating them as a sentient being. So I think
@Charles Phipps has the central question of the episode correct.
And I say again: Nobody asked Archer to change Vissian culture. He was asked to save
one person.