Let me illustrate the dynamic to you so you can step outside your own personally constructed logic labyrinth:

1. The US views some country as an enemy for whatever reason, so attacks it either directly or through proxy or sanctions
2. The US ruling class cares about the perception of their legitimacy, so they have to sell this action to most segments of US society
3. The messaging targeted at liberals focuses on things liberals care about that the targeted country is bad at, like gay rights
4. The targeted country takes this messaging and uses it domestically to sell additional crackdowns on gay rights as anti-imperialism
5. This crackdown is used to justify further action against the country by credulous liberals like yourself
6. The only people who get screwed are the gays, being faced with the twin joys of a domestic crackdown and US bombs/sanctions/whatever

At no point in the liberal mind is it considered that the US ruling class does not give one single tiny shit about the rights of gay people in targeted country, or even proxy country. It is purely and entirely bait to get them to support bombing things. One doesn't have to go too far back in history, if at all, in the US to find actions against gay people that, if they'd taken place in the targeted country, would be used to justify liberal support for bombing the place.