I'll continue with the ending of the endless argument by returning to my point.
Atheists, due to their belief system (or lack there of), would most probably be more inclined to side with legislation and dispersal of funds with a preference towards non-religious organizations. Perhaps even decide with prejudice in matters regarding laws, regulations, and court decisions against religious establishments. In short, having only atheists in government does not adequately represent the interests of all citizens and may in some fashion work against those interests. Whether you consider atheism a belief system or not.