You may have noticed that almost every edit box on the Macintosh uses a fat, wide, bold font called Chicago which looks kind of ugly and distresses graphic designers to no end. All this is true. But graphic designers learned their skills on paper , not on the screen. I learned this lesson after watching a sixty year old man in a usability test painfully trying to edit the name of his street, which was something like Fillmore Street. Notice that the I and the Ls are literally one pixel wide .
L is literally one pixel.
There are very few people who would notice if they mistyped Flilmore or Fiilmore or Fillrnore, and even if they did, they would have a heck of a time trying to use the mouse to select the offending letter and correct it. In fact, they would even have a hard time using the blinking cursor, which is two pixels wide, to select a single letter. Fine, OK, so it takes up more space and doesn't look as cool to your graphic designers. If n is allowed, all n 's are equally likely. A programmer would tend to look with disdain on a program which limited you to 20 open documents.