Describing one’s beliefs is always going to be difficult, but that’s why it’s especially perilous to use existing labels when up against a more rigidly defined belief. I really only point it out because a good many atheists are academic intellectuals who adhere to a more precise definition of the term. It’s part of their identity, much in the same way highly systematic faiths like Catholicism, Islam or Hinduism tend to be toward their adherents. Suggesting that God can exist independent of one’s perception would be offensive to a scientist simply by being irrational.