The thing is, the Nazis killed 6 million Jews, while I don't think homosexuals have killed any Christians because they were Christian. And even if one has, it wasn't an organized act by all homosexuals.
Exactly. Also, Nazism is inherently anti-Jewish and homosexuality is not inherently anti-Christian (and Christianity is not inherently anti-homosexuality for that matter). Even if homosexuals' existence/lifestyle is perceived by some Christians as offensive, they are not doing it for the purpose of harming/offending Christians.