My contention is that regardless of how many people use the word "literally" as a statement of emphasis rather than a statement of fact, they are still incorrect in that usage. If a million people suddenly decided that the word "red" now meant "blue" it would not make it so.
If those million people constitute a clear majority of the language community in question and the change doesn't prove to be a fleeting fad, then, actually, yes it would. That's just how language works.
Why do you think people today talk about 'gay men' without intending to convey any sort of general happiness about the men in question? Or talk about broadcasting in sentences that have nothing whatsoever to do with seeds?
Obviously, people who are used to the older meaning often have trouble accepting a newer one which seems contradictory - and there's of course no reason why they should have to accept it at all. But when you insist on saying 'blue' to a million people who are very settled in the term 'red', it's mainly your own time you're wasting, because they all understand each other just fine.