It is certainly possible to advocate freedom in software and call the system "Linux". I believe that you do. It is also possible to contribute to development of the GNU system in specific ways while calling the system "Linux". It could well be that you have. But it is impossible to be a true supporter of the GNU Project, or a friend of the FSF, while calling our work by a name that attributes it to someone else. That is treating us very badly.
The basic ethical question of the software field is whether your software is free is; that is the question of how you treat the general public. How you treat the FSF and the GNU Project is a lesser question--but it does matter to us. So even while we recognize that you sincerely support the cause of free software, we cannot accept in a list under FSF auspices your practice of attributing our system to someone else.