Ok, but when combined with different prefixes, the meaning changes. For example, agoraphobia is not literally a fear of open space, it's that open spaces sicken and disorient you. Homophobia, similarly, is not a fear of gay people, it is a hatred of them

Calling something or someone gay does not necessarily mean the person saying it hates gay people. It could also be that they know the person or the person doing things would not like to be called gay so it is said to hurt the other person's feelings. I personally believe this for all words. Of course there are some people who will use the term gay and really hate gay people.

That's not what I was saying. I was responding to the original persons comment saying "I'm not homophobic. Phobia means fear. I'm not afraid of gays" simply in an attempt to explain the word to him.