I've taken it upon myself to create this room to provide a place where this specific cited text can be more fully explained to anyone who has trouble understanding the original text.
The text in question: "The last reason became particularly important in the 19th century, when scientific writers—or writers who wanted to be thought of as adopting a 'scientific' attitude—were particularly careful to banish any suggestion that the writer's personality or attitudes had any influence on what was reported. [...]
The passive voice remains to this day something of a fetish in the sciences, particularly in the 'soft' sciences, where there is still substantial anxiety about the scientific status and value of the work done."
By and large, the sciences (hard and soft) and the disciplines which emulate them tend to prefer any literary device which conceals the participation of the writer. The humanities at one time emulated this impersonality but are now mostly forsaking it. Some writers and editors, indeed, actually deprecate any use of the passive; but I think this is largely a reaction to overuse.
There is an excellent discussion of the matter at Duke entitled "Passive Voice in Scientific Writing"; despite its narrow focus its advice seems to me of value to any writer.
The point I was trying to make: Scientific writers wish their work to appear impersonal. One device they employ to accomplish this is the passive voice, which permits the Agent --the person who performs an action--to be ignored. By this means scientists who write about the experiments they perform take themselves out of the experiment. In theory the experiment may be repeated by any one.
This style of writing arose in the 19th century and was widely imitated in the 20th. It has begun to fall out of favor. But it is still followed widely, especially in the social sciences. Physical scientists maintain a rigorous control over variables which is impossible for social scientists. In consequence, the social sciences are often scorned by physical scientists and regarded as inherently 'unscientific'.
This makes some social scientists anxious about their standing in the scientific community. And that causes them to follow very rigorously the literary standards which have traditionally characterized scientific writing, even though scholarly writing in other fields is evolving towards more 'personal' styles, marked in particular by the use of personal pronouns and the active voice.
active and passive voice
active and passive voice