Speculative fiction, science fiction, sci-fi and syfy. What's in a name?

I remember a few years ago when I first heard the term Speculative Fiction. I thought it was great and tried using it, and after a week I realized that as good as it might sound no one knew what I was talking about when I used the term. I would have to explain to them that it meant science fiction and fantasy every time. This led me to the conclusion that it's pointless to try to change the name of something so embedded in the culture especially when there isn't anything wrong with the name to begin with.
But it isn't just a question of using speculative fiction or science fiction, there is of course the controversy of the name sci-fi too, or even Syfy, though I'm not going to get into that. I know that there are those who dislike the term sci-fi because sci-fi is the lasers and robots cartoons on Saturday morning while science fiction is something better. I don't mind this distinction and even use it myself on occasion.
So, that brings me back to my central point. Should we be trying to change the name of science fiction and fantasy to speculative fiction? Would that help convince literature professors that Dune is a valuable piece of literature or would they simply continue to pick out certain books say that they aren't science fiction and so are good enough while ignoring the rest?
At the heart of speculative fiction is the question "what if?" so I ask myself, what if everyone who loved science fiction began to insist it was called speculative fiction. Assuming it worked perfectly there would be some changes. The shelves in the book stores would eventually be changed to say speculative fiction rather than science fiction, which would help eliminate the bizarre situations where you would find "The Hobbit" directly under the title science fiction. (Although it did lead me to an interesting story idea about genetically engineering hobbits).
Beyond that though I don't know that it would matter. I have trouble believing that many literature professors would be fooled into discussing the metaphors and themes of "Ender's Game" in class even though there is plenty to discuss. They would simply look down their noses at a marginally more accurate name for a genre the same way they look down on science fiction now.
In the end the only real solution for the stigma attached to science fiction is for us to stop being embarrassed by enjoying sci-fi, because in large part the reason that people look down on science fiction is because the people who enjoy it look down on it. Often we are unable to see just how good these books are and if we can't explain why science fiction is valuable without changing the name why should we expect that they know?