Andy Hertzfeld, one of the original engineer of the Macintosh:
The most controversial part of the Control Panel was the desktop pattern editor, which I had rescued from its earlier stand-alone incarnation. Users could select from a couple dozen prefabricated desktop patterns or edit their own in fat bits. It was this latter capability that caused problems, as it was pretty easy to create ugly, abominable patterns.
Bill Atkinson complained to me that it was a mistake to allow users to specify their own desktop patterns, because it was harder to make a nice one than it looked, and led directly to ugly desktops. But I thought that users should be free to do as they pleased, since it was their desktop, and it was easy to revert to one of the built-in patterns. Bill cared mo st about MacPaint, and didn’t want a potentially ugly desktop pattern marring his creation. So he made MacPaint allocate a window that was the size of the screen when it started up, and filled it with the standard 50% gray pattern, making his own desktop covering up the real one, thus protecting the poor users from their rash esthetic blunders, at least within the friendly confines of MacPaint.
Many of today’s computing tradition began with personal obsessions such as this one.