>> > Having `this' in a manpage is perfectly good typography, No, it's not – unfortunately. Today, this is only the TeX way to enter left and right single quotes. However, there exist virtually *zero* fonts that display ` as an acceptable left quote in a typographical way. Previously, ` and ' were kind-of symmetric in many bitmap fonts, but this has changed.
I'm against many changes caused by 'modern' features, but in this very point we have to update everything and follow the new rules. Note also that groff is a GNU program, and the GNU standards have changed, too. For example, in error messages the recommendation is no longer to say `foo' but 'foo' Werner