Not the ’70s per se, but rather the typographical dumbness and/or inexcusable laziness inherent in having the apostrophe in such instances going the wrong way.
For once, uncomfortably, I have to put myself among the Blame the Computer crowd. Specifically, I blame “helpful” applications that insert legitimate quotation marks and apostrophes into our sentences. That and dumbness and laziness (see above).
For the most part, I appreciate having " and " turned into “ and ”, but the problem arises when the program gets to ' and ’. See, Word, PhotoShop, InDesign, etc., don't know an apostrophe from a single quote mark. So it looks for cues from the structure of a sentence. If it guesses that the user wants single quotes around a sentence, or a word or words within a sentence, it will correctly produce something like this:
“The quick brown fox jumps over the ‘lazy’ dog.”
Good enough. Likewise, when the program detects a single quote mark within a word, it correctly deduces an apostrophe is the order of the day:
“The quick brown fox’s kits jump over the ‘lazy’ dog.”
But things go entirely off the rails when those sentence cues don’t hold. For instance, a couple of paragraphs ago, when I wrote “ and ” ? I had to go back and make sure the second quotation mark curved the right direction. Good ol’ Microsoft Word wanted to give me “ and “ … because the space after and made the program thing it was the beginning of a sentence, phrase, or word. It gave me the right quotation mark, but in the wrong context.
And when I wrote good ol’ Microsoft Word back there? Word correctly determined that I needed an apostrophe in ol’, since it indicates a missing letter, and delivered the goods. But it—and nearly any other program you’d care to name—gives out entirely when it comes to something like Welcome to the ’70s. It’s the space in front of ’70s that throws it, making it think that a single quote mark is needed rather than an apostrophe. And it delivers the wrong goods.
The fix is really very easy: You type ‘’70s --> , and then go back and delete the --> ‘. Alas, computers have convinced a great many people that anyone who can use turn one on is a writer, editor, designer, typographer, you name it, and so a great many people who don’t know the difference between ‘ and ’ – and are too ignorant to know they don’t know – are misusing left-hand single quote marks as apostrophes. Luckily, it’s almost certain that a majority of their readers or viewers don’t know the difference either. But for those of us who do…nails on a blackboard.
That said: Kudos to the designer of the image above, or a semi-astute editor or art director, for not sticking an apostrophe before the s in ’70s. If ‘70s is like nails on a blackboard, ‘70’s would be like an icepick in the ear.