That 15-year-ago mark is interesting to me, because that was just about the time when I switched to proportional fonts. I recognize that I'm in a tiny minority

That 15-year-ago mark is interesting to me, because that was just about the time when I switched to proportional fonts. I recognize that I'm in a tiny minority: the vast majority of developers code in monospaced fonts. That's one reason why I value an editor that makes it easy to switch between a proportional font and monospaced, so I can code in the font I like or switch to a monospaced font when necessary. One of the few that does this well is Komodo, where each "theme" includes both proportional and monospaced fonts, and you can easily switch between them. (I just wish IntelliJ IDEA did this!) It's also why I wouldn't presume to use a coding standard that worked only in a proportional font but looked bad in monospaced. But to my eyes, a coding standard that works equally well in proportional and monospaced fonts is superior to one that works only in monospaced. I must respectfully disagree that "It turns out that proportional fonts are designed for text, not code." All of the code I've written in the last 10-15 years is just as readable in a proportional font or monospaced. It really makes no difference at all which kind of font you read the code in, if the coding standard was designed to support both.