How has using apostrophes in plurals caught on so?

I'm curious. How has wrongly inserting an apostrophe to indicate a plural noun become so widespread?

I was born in the 60s. Thirty years ago, in England at least, the only time you'd see it would be in greengrocers (Potato's 50p/lb - grrrr!). Now, it's everywhere. An extraordinary and increasing proportion of people seem to assume that it's required for almost every plural.

The thing is, it can't be laziness. It requires more effort, not less, to type the extra character, when in the majority of cases, an 's' is all you need.

How did it start? And how did it catch on?

Edit:

I should say, I've often suspected that it was originally a hypercorrection, like 'between you and I', also now widespread.

I suppose, that the more people see the construction, the more people that haven't either read widely (an increasing proportion of young people, I'd speculate) or been taught well, will assume it's correct and propagate it further. I suspect social media of contributing substantially to this process.

I think what I'm really asking, is, does anyone know of any actual evidence to support or refute these hypotheses?