This sort of statement is really contingent on the given region you're speaking to. Homophobia is largely a reflection of introduced Abrahamic religions in the area. I'll have to find an article that I was reading about it
Now I've read that many times. But I don't think it's actually true. The monotheists codified anti-homosexuality, but practically all cultures had been hostile to it since the age of agriculture and the rise of male-dominant societies it led to.
One exception, out of thousands, is the Greeks. They seemed fairly accepting of homosexuality. Other examples I read about are pretty bad ones. The Romans and Japanese were accepting of homosexuality in some circumstances, and as long as people kept quiet about it. But they weren't open to it the same way modern Western cultures are.
The monotheists just made official the popular sentiment of their time.