Those things can be spoken out against while including believers. That's what the whole idea of secularism entails - it's about building the wall between church and state while still including religious people who understand the importance of doing so. The people who wrote the U.S. constitution were religious people, and they understood as well as any of us that a secular society includes not only freedom of religion but also freedom from religion.
The wall between church and state needs to be upheld, but we don't need to divide people in the process. A movement for atheism will only compartmentalize it and create just as many people against it as there are parading under it. If you really want a movement to represent you, join one of the many
secular humanist organizations. If you want to attach yourself to an idea, attach yourself to skepticism or rationalism. If you want to devote yourself to something, become a scientist or a humanitarian.