[ochrist]

The difference is important, because there are examples of GNU without Linux (eg. GNU Hurd) and Linux without GNU (Android comes to mind).

[TimTheTinker]

The year of Linux on the desktop (and its broader adoption) is in part slowed by fragmentation across distros and weird names.

You wouldn't tell your mom about this great operating system she should use named "GNU/Linux". That's bad marketing.