It is true that all the tools you mentioned are under the GPL. However, software you develop with Linux, GCC or Emacs typically do not inherit the GPL (there are special allowances in the Linux license and you don't link against the other tools). If you link against the GPL version of Qt, you inherit the GPL license.
It is true that all the tools you mentioned are under the GPL. However, software you develop with Linux, GCC or Emacs typically do not inherit the GPL (there are special allowances in the Linux license and you don't link against the other tools). If you link against the GPL version of Qt, you inherit the GPL license.
So the situation is not comparable at all.