I literally could care less.
Now don’t you start, young man! 
While we’re on this topic: What is the correct spelling for the popular slang for disrespect?
Is it “dis” or “diss”? (I favor “diss” because it makes the pronunciation clear. “Dis” looks like it would be pronounced “diz”)
“Literally” is the only misused word that I particularly care about, because it leaves an irreparable hole in the language. Use any other word figuratively, and if your meaning is unclear, the person to whom you’re talking can ask if you mean it literally. Once you answer that question, the meaning becomes clear, and no permanent harm is done. Using the word “literally” itself in a non-literal way, however, removes that ability, and so makes the word “literally”, as well as every other word used figuratively, unclear.
Yes, they literally do.
Oh, good God. No they don’t. It does not mean “figuratively” used in this manner. I know, because I use the word, and I DON’T MEAN “FIGURATIVELY.” And no, there is no confusion, because it’s used in hyperbolic senses where it’s obvious whether it’s being used hyperbolically or literally. Come on. Let’s take this to another of zillion threads. Christ on a cracker.
The abbreviation to “diss” someone was common for a while (80s?), although I think it has fallen out of use. It was only used as an abbreviation for the verb.
Nonsense.
I still hear it around, but, yes, that’s when it seems to have had its heyday, though into the 90s, too. Somebody upthread asked how to spell it, and I spelled it “diss” in my post, but looking at some dictionaries online, it seems “dis” is perhaps preferred.
Good grief, are we really doing this again. What complete nonsense.
“That was literally the worst play I have ever seen.”
“Do you really mean that literally?”
“Well, no, but it was pretty bad.”
What “irreparable hole”, exactly?
And, again - the word “literally” in the first sentence obviously does not mean “figuratively”. It’s an intensifier, synonymous with “absolutely”.
Ah, sorry - I didn’t notice that you’d already mentioned the abbreviation.
Doesn’t the fact that you need to interrogate the speaker to find out what he really means indicate that this isn’t an appropriate use of the word? Maybe it really was the worst play he’d ever seen. Everyone can say that about one play and mean it literally. This is one of the cases where it really is unclear whether the word is being used literally or as an intensifier.
No. I think the very ambiguity is why it’s a “fun” way to intensify a claim, and that’s why it has caught on. My point was that, contrary to Chronos’s assertion, it’s always a trivial matter to clarify the speaker’s actual meaning in the rare case that the distinction actually matters. There is no “irreparable hole” in the language.
Perhaps a better example, where a metaphor is involved.
In discussing Trump:
“If the Senate fails to pass a healthcare bill again, Trump’s head will literally explode!”
“Literally?”
“No, of course not. Are you an idiot? I just mean he’ll be extremely mad.”
In discussing the movie Scanners:
“There’s a scene where a guy’s head literally explodes!”
“You mean really explodes, like blood and brains go everywhere?”
“Yes, it’s awesome!”
In the Trump case, the elucidation would never actually be required, the meaning is unambiguous from context. But that kind of usage means that in the Scanners case, perhaps elucidation might be required. But again, there is no “irreparable hole”. It’s perfectly easy to clarify what meaning is intended.
The idea that this use of literally is creating such ambiguity that nobody can understand each other is just silly.
Well, I guess we’re off again! 
I was thinking of starting a thread in IMHO to discuss McWhorter’s bad arguments on this, but I’ll deal with your bad argument right here since you brought it up.
Your example rather dramatically proves my point and disproves yours. Is “literally” here being used in the original, correct sense or is it just an intensifier? You’ve unintentionally provided an example of real ambiguity: in this example it’s impossible to tell! Why is it not plausible that this is actually, literally the worst play this person has ever seen? If it’s synonymous with “absolutely”, that would be my interpretation of what it does mean. OTOH, the speaker might just be using the word as a bogus intensifier, as you surmise. But it could easily be either, and we have no way of knowing. The word “literally” has become ambiguous and lost its value of clarity. That’s the irreparable hole.
ETA:
By that remarkable standard, random grunts are the height of linguistic achievement – because it’s a trivial matter to clarify the speaker’s meaning using actual words that still do have meaning.
Everything that you’ve written is also true of any metaphor. Any metaphor is counterfactual, it says a is b, when it means a is like b. It’s impossible to know without context whether something is literal claim or a metaphor.
So, do you also disapprove of all metaphors?
Well, I tried.
Except asking, you mean? On the rare occasion that it’s not clear from context.
You have glossed over the point I made that the superficial ambiguity of this use of the word literally is the very attraction of the usage, and part of the reason it has caught on.
This is terribly misguided. Good metaphors enhance the communicative power of language by evoking vivid and often emotional imagery. Good metaphors are thus the exact opposite of ambiguity or obfuscation.
I glossed over nothing. I specifically indicated that if you have to seek clarification on the meaning of a piece of language, then it’s poor language with poor communicative power.
OK, now try this.
“That was the worst play I’ve ever seen!”
“Literally?”
“Yes, literally!”
Now, did the first speaker mean it literally, or did they just think it was an intensifier?
I never said that the word “literally” is used to mean “figuratively”. I said that it is used figuratively.