Much of the Holocaust stories focus on the Jews because the main objective was the destruction of the Jewish people, as well as others. Consider that the pre-Holocaust Jewish population of Europe was 9.5M representing 60% of the world's Jews and some 6M were massacred, the numbers were staggering. It also didn't help that after this devastating rampage, anti-Semitism throughout the world was still at an all time high, and the Europeans that did nothing during the Holocaust, now pushed their problems onto another part of the world, Israel. IMO, I believe they were hoping the job would be finished. Which leads me to the gays...
After the war, many were not freed, they were actually sent to prison and those who did not end up behind bars were quiet about their persecution because being gay in the mid-40's was still illegal and that, of course, didn't change until the late 70's in the US and different parts of Europe. It wasn't until the mid-90's before we actually started to see conversations about the GLBT experience as a community, then the horrors of the Holocaust were revealed to many. There are still many who see what happened to gays (as it was almost exclusively gay men) as "understandable". Though recognition of the tragedy inflicted on gays are only now coming to fruition, it is largely due to the continued homophobia through the world. Even today, we see people mock the remembrances in one way or another.