I was asked this question in an interview once, about whether the Satanic aspect damages the cause. It was in specific reference to the Satanic Temple’s After School Satan initiative. I asked the interviewer if it were the After School Humanist Association whether I would even be there being interviewed. His response: “Nope.”
Speaking only for myself: not only do I embrace the symbolism of Satan as someone who stands up to unjust authority, who stands for enlightenment over blind obedience, but I feel that society’s own biases and preconceptions are turned on their head when everyone is forced to deal with the idea of compassionate, justice-seeking Satanists in a way that is not accomplished with the more nebulous, safer labels of secularism, humanism, or atheism. Clarity and focus are some of the hallmarks of Satanic Temple action, and I think that type of pragmatism is evident in the ‘branding’ itself.
On some level, too, the importance of the question of optimization of effectiveness becomes diminished. At its core, The Satanic Temple very much is a religion. It is not a faith-based religion, but its members do have a set of shared principles and goals. Of course we want to be as effective as we can, but our choice to identify as Satanists is just as much about us as individuals and as members of a religious community as it is about our activities in the context of the broader fabric of society. At some point, we just have to be comfortable with who we are, and society must afford us the same respect for our aesthetic, moral, and philosophical choices that it grants to other religions.
Not to shamelessly plug my stuff, but I addressed some of these issues (and many more) in my book, too.