“The habit of obscurity is partly caused by a settled disinclination among public servants to give a definite refusal even where assent is out of the question; or to convey a vigorous rebuke even where, in private correspondence, any person with self-respect would feel bound to do so.”

Source: The Reader Over Your Shoulder (1943), Ch.4: "The Use and Abuse of Official English"
Context: The chief trouble with the official style is that it spreads far beyond the formal contexts to which it is suited. Most civil servants, having learned to write in this way, cannot throw off the habit. The obscurity of their public announcements largely accounts for the disrepute into which Departmental activities have fallen: for the public naturally supposes that Departments are as muddled and stodgy as their announcements.
The habit of obscurity is partly caused by a settled disinclination among public servants to give a definite refusal even where assent is out of the question; or to convey a vigorous rebuke even where, in private correspondence, any person with self-respect would feel bound to do so. The mood is conveyed by a polite and emasculated style — polite because, when writing to a member of the public, the public servant is, in theory at least, addressing one of his collective employers; emasculated because, as a cog in the Government machine, he must make his phrases look as mechanical as possible by stripping them of all personal feeling and opinion.