If we view language as a living organism, then change is just part of that. The development of limbs in our ancestors could hardly be considered a mistake. It was merely a development.
Using “literally” as an intensifier is merely a development. The word “awesome” used to mean “filled with awe”. It clearly doesn’t meant that anymore. In a much earlier stage of English, the equivalent of “hound” meant “dog”. The meaning changed over time.
Language viewed from the descriptivist point of view doesn’t treat these changes as mistakes, only changes. Was it a mistake that English dropped conjugation or the second person plural? No, it just changed.
If you are thinking to yourself, “But these people are saying something weird and different and it goes against convention. Look at what the dictionary says!”
All language is convention. We use the word “dog” because that is the word everyone uses. For some reason people started refering to the hairy four legged creature as a dog and now everyone does.
Now when you say that language is change, some people misinterpret this to mean that anything goes. That is not how it works. Language is convention. If I started chinging ill my A’s into I’s then my writing will be going igiinst convention ind will confuse ind innoy people. Of course, you can still read it and understand it because the change is not large.
But to use language effectively, you have to be aware of current convention and abide by it to make sure that you are understood and don’t confuse people. You can’t start calling a computer a dog and expect people will understand what you are trying to say.
But these conventions are very loose. Much looser than a lot of people would like. Is it “colour” or “color”? Depends where you are. Is “aint” a word? It is in many places and in others it isn’t used much, if at all.
Can you use “literally” as an intensifier? Well, this question is besides the point. People DO use “literally” as an intensifier. Ignoring that reality is like refusing to believe that birds exist.
You can argue that it robs us of a word which means “this is totally and 100% true” but there are ways of communicating this such as “I was no tired that I simply couldn’t move from the couch” or “I was so hungry I would have actually eaten anything that was put in front of me”.
I really don’t understand the vitriol people through at this different use of “literally”. If you really do care about language, then spend your energy on useful things, like helping people write more clearly and expressively. If you just want to scream at the fact that the world is changing, then go ahead. People havebeen lamenting change since time immemorial. But here we are, speaking dialectal Proto Indo European and everything is going pretty alright.