Everyone has a language peeve. Mine is "literally," a great word with no close synonym. When used as a mere intensifier or to mean simply "It felt as though..." it has almost no kick at all. And when misused, it can be spectacular: what Lindsey Graham recently said of an American program to turn weapons-grade plutonium into reactor fuel for peaceful energy. Truly this is a good thing, but Graham probably shouldn't have said that "the United States is literally taking nuclear swords and turning them into plowshares." My first thought was that it was pretty sweet that DARPA had finally invented nuclear swords. My second was, "But who wants a nuclear plowshare? Would you eat vegetables out of a field plowed with one?"
So I'd like to keep "literally" meaning "not figuratively," and every time I see it used to mean "figuratively" I sigh a little sigh. You certainly have your peeves too. Maybe it's "Between you and I." Maybe it's "Jenny and myself are going to have to think that over." There are enough to fill many books, and indeed they have filled many books--some of them bestsellers. All of us who love language hate to see it used incompetently.
But I got the idea for my recent book by noticing that there seemed to be more than defending the language going on when people talked about this or that usage. Take Black English: linguists have long known that it's a regular dialect of English with its own consistent internal rules, like Scots or Southern White English. But while most people know that it's unacceptable to make fun of someone's skin color, they feel free to make fun of their language. Zach Galifinakis has a joke about using lots of Axe body spray, though since he lives in a black neighborhood, he calls it "Ask". It's a pretty good joke, and he defuses it by saying "If you didn't get that, you're not a racist." But many people really think that "aks" in Black English is mouth-breathing stupidity, rather than merely dialectal. It has a long history in English, even appearing in Chaucer: "I axe, why the fyfte man Was nought housbond to the Samaritan?"
In other words, there's nothing wrong with treasuring good English. But people confuse "grammatical" and "good." "Correct" English is often plodding or incompetent. Meanwhile, many people who aren't one hundred-percent fluent in standard English are nonetheless brilliant, charismatic and persuasive--I should know, as my father, who could charm a fish out of water, was an earthy, profane southerner, and not exactly Henry Higgins when it came to "proper" English.
Too many people take the step beyond caring for their language to enjoying laying scorn on others who use it differently. This is several different problems at the same time. One is, as mentioned, the bigotry against dialectal English, apparently the last form of prejudice acceptable even in polite, liberal company. It's important for African-Americans (as for all Americans) to master standard English, but part of that bargain should be accepting that their language, like my dad's Southern White English, deserves a place too, and one without scorn.
The second way in which people go wrong with language peeving is simply picking the wrong peeves. There are many "rules" that are "known" to copy editors and sticklers everywhere that simply aren't so. Famously, the ban on splitting infinitives and another on ending sentences in prepositions have both been known to be bogus by quality grammar-book writers for at least a century. But these "rules" seem unkillable. So do many other more rarified ones, which seem to live on so that copy-editors can one-up each other: Use "each other" for two people but "one another" for three or more. Use "that" for restrictive clauses like "the house that Jack built", but "which" for non-restrictive ones like "the house, which Jack built,..." But these and so many others are not "rules": they began life as one grammar-book writer's fetish and made their way into print to plague us with an endless game of grammar-gotcha.
So by all means, treasure language. But don't let your love for good English mean disdain for people who don't use it exactly as you do. Part of a healthy love for language is an understanding of the many different forms it takes. Dialects are healthy parts of real communities. Changes to a language are natural, not simply degrading. Even if my friend "literally" doesn't survive, quality English will.