I think most people simply don't get it if something doesn't affect them. As someone who grew up been made fun of for being gay, who constantly kept hearing from the media that gays are perverts, whose parents thought that gay equalled doing drugs or being a prostitute, hearing my friends say "oh that's gay" for something that is terrible annoys me beyond words.
You might think that words are meaningless, but just because you have a tougher skin or most likely because those words have nothing to do with you, it doesn't mean that others aren't affected. You might dislike LGBT communities or organizations but it's thanks to them that many gay men have significantly better lives over the years.
It's like joking about AIDS or cancer. If you or your family/close friends have/had neither, it's no big deal. If you've went through it and it was hell, it might affect you differently.
Sure, some times I say the "r" word without thinking and then I realize that the brother of a friend of the group is mentally challenged. Well, it might be an inconvenience, but since I know that it bothers them, I avoid it. I much rather feel like I have less freedom than hurt people even unintentionally.
