On top of all that America also just actively persecutes queer people. People will say "oh that's just the republicans" as if that isn't half the country and it's not just the republicans, but a large group of democrats. Then they'll say "oh, but we're not as bad as [enemy of the week]" which funnily enough is actually a whatabouterismerino, but also not really a valid argument if you're saying it's okay to bomb a country if they're mean to queer people. So it's okay to be kinda mean to queer people?
On top of that there's also the fact that some of the US' closest allies are countries like Saudi Arabia, not to mention the many far right anti-lgbtq dictators the state has installed over the years.
On top of that the US has only recently gotten "good" on queer rights. Homosexuality wasn't decriminalised in the whole of the US until 2003 (and we're not talking some weird little forgotten law, it wasn't until a supreme court decision forced several states to finally stop being bigoted.)
At the same time the GDR had decriminalised homosexuality by 1957 and with constitutional reform fully legal by 1968 
The GDR did this despite inheriting the nazis legal code (according to a wikipedia source which I will not fact check.)
Would it have been acceptable, nay morally right, for the GDR to bomb the US?
definitely, but not just because of da gays
Leftwing and progressive ideas are co-opted by liberals as the new version of the White Man's Burden. I think I first saw someone make that observation here on Hexbear and it's the perfect description. In the 1890s the US justified its behavior in Asia and Central and South America by "taking up the White Man's Burden" to "spread democracy and culture to the savages." It was the same attitude of "kill the Indian and you save the Christian."
Since 9/11 (and before...well, most of the States' existence), Americans have regurgitated this shit into a new form where they call Arabs "homophobic and sexist," while the US does the same bullshit at home. Is there really a difference between some chud shooting up a gay bar while police watch and police arresting a couple before executing them for being gay? What about the hundreds (or thousands, I haven't checked lately) of untested sexual assault kits needed to prosecute predators? Sexual assault in the US is legal by de facto because there's so much fuckery in the way of getting survivors justice.