What I was attempting to express (maybe not so well) is that the process of classification of people which assumes them as being motivated by any default, fixed beliefs (or disbeliefs), in modern times, is not reflective of the demonstrable human ability of altering motivations on a basis other than fixed beliefs. In fact, classifying people that way and denoting those 'classes' by using the '-ist' suffix, sets up the path towards nothing more than discrimination.
The purpose of discrimination on the basis of fixed beliefs is certainly not the purpose behind science's classification system, and so any attempts to imply equivalence between the two, should encounter serious objectively based evidence counter argument. (I think we might agree on this?)
I find acceptance of the term of 'atheist' tantamount to the acceptance of humans being nothing more than what they believe, with 'atheism' simply being denial of some other assumed, preferred belief (ie: 'theism'). I understand and accept some atheists try to distinguish atheism from that, by saying it represents an absence of belief, however, this still indulgences a conversation which centers around belief systems.
Any notion which sanctions or certifies any belief system, is where I choose to take my stand.