The reason why discourse of sexual orientations brings its own kind of repression and unfreedom is that it is essentially a discourse of heterosexism, which posits a heterosexual majority, who are supposed not to feel attracted to same-sex love and lust at all, and homo and bisexual minorities. That is one of the chief sources of "sex panic" under the hegemony of discourse of sexual orientations. That is why propagation of this discourse is not desirable.
Moreover, taking the middle way between economic determinism and discourse analysis, we can readily see that there has to be, and indeed is, a great deal of sexual gap between the global North and South, which are not at all on the same level of economic development.
Finally, many observers from the "West -- soldiers, scientists, missionaries, businessmen, colonial and neo-colonial civil servants, etc. -- who wrote about sexuality in the rest of the world in the past -- especially from the late nineteenth century to the mid twentieth century were generally disgusted by what they saw, especially the absence of the bourgeois heterosexist norm and prevalence of other forms of sexual practice such as sodomy and polygamy. They thought of such sexual differences as a matter of civilizational hierarchy -- the West ranked higher than the rest in their opinon -- which became part of the themes of the Civilizing Mission of colonialism and neo-colonialism.
Today, many observers from the West -- roughly the same categories of people, to whom human rights NGO officers are added -- are again disgusted -- but this time by the dearth of out GLBTQ communities (notwithstanding the fact that they weren't regarded as "normal," let alone desirable, in the West itself only a couple of decades ago). The standards of judgment have changed, but the power relation between those who judge and those who are judged -- the West judging the rest -- and how the judgment promotes imperialism remain the same. -- Yoshie