...and I agree that there exist people, who use (or rather abuse) evolutionary biology to promote atheism (e.g. Richard Dawkins). But as far as I know Richard Dawkins does not post here on FR. The word “Darwinist”, uttered as a politically-charged expletive, is used to brand as godless commies those, who dare to debunk ‘creation science’ or protest the ‘I am a better Christian than you’ attitude of some sectarians.
Or it's used to separate sane, undogmatic people who accept evolution and common descent but understand the sanctity of life and realize that there is a transcendental aspect to our existence far more important than material survival from the Godless commies, in which case it is quite useful :-)