At least he wasn't a self-hater, he just never believed in G-d. "Humanistic Judaism" is still better than completely renouncing one's Jewish identity. It gives atheists a way to stay connected to at least some semblance of Judaism when they otherwise would have left it altogether. Although it's not real Judaism, there is something positive to be said about it in the context of American Jews. I had "Jewish" friends who I would be delighted to hear joined "Humanistic Judaism."
But you're right, a "Rabbi" who is a homo and an atheist is a sick joke, these people need to stop referring to these people as "Rabbis". What's next, satan worshippers being labeled as "Rabbis"?