Aaron Seigo talks life, free software and reinventing the Desktop (ComputerWorld)

The other packages, like GCC, Gnome and the kernel are used both by Ubuntu and Kubuntu. I
think the point Canonical is trying to make is that there are many people who are paying for
long term support for Ubuntu, and that the cost for supporting e.g. Gnome and GCC for 3 years
is split up among all these people, butthe  number of people willing to pay for Kubuntu
support for 3 years is somewhere in the vicinity of none, making it economically unsound.