That line of reasoning isn't convincing to me (though I have no data to confirm or deny it); CS could still be a more prolific paper writing community, just that papers compete more for citations. In CS if I want to cite something, I have my choice of 10 papers from the same era from roughly the same group of people saying roughly the same thing (some might prefer to cite earlier papers, as the "original", others might prefer later papers as the ideas are more clarified). In other fields, there might be one "standard" paper to cite for a era/topic/group.