You're no longer talking about ASCII. ASCII has only a double quote, apostrophe (which doubles as a single quote) and backtick/backquote.

Note on your Mac that the Option-{ and Option-}, with and without Shift, produce quotes which are all distinct from the characters produced by your '/" key! They are Unicode characters not in ASCII.

In the ASCII standard (1977 version here: https://nvlpubs.nist.gov/nistpubs/Legacy/FIPS/fipspub1-2-197...) the example table shows a glyph for the double quote which is vertical: it is neither an opening nor closing quote.

The apostrophe is shown as a closing quote, by slanting to the right; approximately a mirror image of the backtick. So it looks as though those two are intended to form an opening and closing pair. Except, in many terminal fonts, the apostrophe is a just vertical tick, like half of a double quote.

The ' being veritcal helps programming language '...' literals not look weird.