I love the Linux world’s tradition of less serious names, in general.
I guess when the OS is free, you don’t need to get the marketing people involved as much.
The kernel was almost named Freax. Then there’s GNU, Slackware, KDE which was originally the Kool Desktop Environment, The GIMP (released 1 year after Pulp Fiction), …
It’s often due to the devs creating it as a hobby project and giving it a light-hearted name to show it’s nothing professional or important - and then it becomes important later.
My favorite right now is RebeccaBlackOS, which is the only current distro built around Wayland’s reference compositor Weston, showcasing all the capabilities Wayland has.
Unlike Hannah Montana Linux, it has no Rebecca Black theming at all. It’s just called that because the dev is a fan of hers.