I had a user in there mid 50 who kept complaining about the fonts in a custom application. Turns out he was having vision issues and after getting some reading glasses he stopped having any issues.
PS: I have a high resolution screen and changed my default zoom the make the vast majority of websites readable. True, it would be nice if websites stuck with readable percentage based fonts, but until then it's an easy change. And, IMO far more productive than complaining on HN which the author might not even read.
You know how many people here would have had to zoom in?? Are you new to the internet?? /end nerd rage/