No One Uses "Literally" to Mean "Figuratively"

Every now and then I come across someone claiming that the word "literally" is now being used as a self-antonym. In other words, it is being used to mean "figuratively". Consider the following sentences:
1. And when he gets into the red zone, he literally explodes. (from a football announcer)
2. [Tom Sawyer] was literally rolling in wealth. (Mark Twain)
3. [Jay Gatsby] literally glowed. (F. Scott Fitzgerald)
4. [A certain Mozart piece was] the acme of first class music as such, literally knocking everything else into a cocked hat. (James Joyce)
As you can see, this isn't that new a phenomenon. It goes back at least a couple hundred years. There seems to be an incredible amount of outrage about it in certain spheres. Vice-President Joe Biden gets made fun of a lot for his excessive use of the term this way. But consider the following sentences:
5. When he gets into the red zone, he really explodes.
6. He was really rolling in wealth.
7. He really glowed.
8. The piece of music was really knocking everything else into a cocked hat.
Those sound perfectly fine. The word "literally" and the word "really" both normally indicate some genuineness to something. Yet both are used in situations where it's not really or literally the way it's being said to be. Both are wrong, if the words are being used literally. But they aren't being used literally. They're being used as intensifiers. He doesn't just glow. He really glows. Saying he literally glows is doing something similar.
What is not going on here is the use of these words as self-antonyms. The seventh sentence above does not mean "He doesn't really glow." That sentence means something very different. Nor does the third sentence mean " He doesn't literally glow." That sentence also conveys something different. These words are being used as intensifiers. Saying "he doesn't literally glow" or "he doesn't really glow" is not intensifying the sentence "he glows". But 3 and 7 are intensifying it. So the word is not being used to mean its opposite, in either case.
The word "literally" is not being used to mean "figuratively". If it were, then we would expect 3 to be synonymous with:
9. He figuratively glowed.
But the two are not synonymous. 3 would not be used if you intended to be talking about the linguistic properties of the word "glowed". A sentence like 9 is commenting on its own language. A sentence like 3 is doing no such thing. Furthermore, 3 has the intensification that 7 has. 9 does not. These sentences are not at all equivalent. If the word "literally" were being used to mean "figuratively" then they would be synonymous. What's actually going on is that the word is being used as an intensifier, the same way the word "really" gets used. That's not at all the same thing as being used to mean "figuratively". I suppose you might say that the word "literally" is being used figuratively. But that's not the same thing being used to mean "figuratively".