Most racism, sexism, homophobia, etc., is implicit, meaning that it's not conscious and based in the cultural narratives and stereotypes that the person grew up with. That doesn't make them any less insidious however. We do need to be mindful of how we use words, and particularly to investigate where we casually marginalize others without even realizing it due to societal programming. It's the only way that these things can ever change. Words are incredibly potent and they do hurt. They also create the world that we live in.