Why not contribute? (to GCC)

[Alfred M. Szmidt]

   IANAL but the copyright assignment is probably necessary for the
   FSF to have the rights to change the license at will (within the
   limitations allowed by the copyright assignment). If there are many
   copyright holders, like for say the linux kernel, a change of
   license requires the approval of at least all major copyright
   holders, IIUC.

This is incorrect, anyone can upgrade the license for GCC (and the
rest of the GNU project), since GCC is licensed under the `GPLv3 or
any later version'.  Linux on the other hand is explicitly licensed
only under GPLv2; i.e. it lacks the `or (at your option) any later
version)' clause.