I agree that the only correct character to use as the apostrophe should be the actual, ASCII, 0x27, ', apostrophe. The problem people have with this is that it looks horrible typographically because fonts generally have a vertical symbol (so it can also work as an opening or closing single quote). The correct fix is to use fonts where the apostrophe looks like a closing single quote. Obviously that's a disaster for coding ... so code with a console font. There are plenty of common fonts that are ambiguous about O and 0, and about 1, l, and I, so why care about apostrophes looking the same as closing single quotes? There are separate acute accent and prime symbol characters for use when those are required.
Editing prose (with a console font) is way easier when the open quote, close quote, and apostrophe characters are all different. Spell checkers aren't confused about closing quotes being part of a word and checking for broken pairs of quotes becomes trivial with regular expressions. LaTeX does this right, accepting an ASCII apostrophe in the input and producing the correct output. All the "smart-quote"-like WYSIWYG solutions are always breaking on edge cases.