I don’t see how to interpret your comment in a way that doesn’t say “their goal should be encouraging people to be principled, not being being principled themselves.”
You can use a tool of a system you disagree with to raise concerns against that very system. There is no contradiction here, only pragmatism.
GNU tools such as gcc were originally developed using proprietary software until the GNU fabric was dense enough to allow bootstrapping. How else can you achieve anything at all, really?
