Pointed from an answer to a (possibly related) question, I came across this graphic, and I'm shocked how many linux distributions currently exist.

However, it seems that most of these distributions are forks of already popular distributions with minimal changes, usually limited to themes, wallpapers, buttons, the kind of stuff most people probably wouldn't see as a reason to fork a Linux distribution.

Of course, someone will always say "Opensource is also about the freedom of choice", and while I wholeheartedly agree, I do not believe that this is a valid reason to fork an already perfectly working Distribution into a new one, which might possibly result in less security/stability due to smaller group of developers.

There's another problem: Those, who want to switch to Linux, are confronted with a neverending list of Linux distributions, and wonder rightfully which they're supposed to chose (infact, I was facing that problem before I've discovered Ubuntu).

There might be (very few) valid reasons to fork a distribution:

• Specializing on a particular topic (FOSS Only, work-related topic (i.e., for a Hospital), etc)
• An exceptional architecture, that requires a special set of software
• Use of non-FOSS, propietary technology, and such

But even with these points in mind, it would still seem easier to create a subdistribution with the required changes, such as XUbuntu with XFCE4, KUbuntu with KDE4, Fluxbuntu with Fluxbox, etc.

So, why exactly do we need so many distributions?