The explanation seems to be that it looked good in some old fonts. But I think it was always some kind of abuse. On old Typewriters the accents were usually used for accents (é è). They didn't move the cursor, so using them for apostrophes wasn't that comfortable and interrupted writing flow. Accent + space looks a bit like a quotation mark, but the right place of an accent is usually on top of a letter.
The explanation seems to be that it looked good in some old fonts. But I think it was always some kind of abuse. On old Typewriters the accents were usually used for accents (é è). They didn't move the cursor, so using them for apostrophes wasn't that comfortable and interrupted writing flow. Accent + space looks a bit like a quotation mark, but the right place of an accent is usually on top of a letter.