George Orwell has a famous essay called "Politics and the English
Language," which is widely cited, discusses, and endorsed in
all manner of situations. Across the intellectual landscape, in
many different contexts, people endorse it as wonderful writing
advice and an excellent critique of vapid political discourse.

Orwell puts forth several rules for clear writing, all of which
are motivated by a modicum of reasoning. All of them, when
followed to their conclusion, can only produce confused and
impenetrable prose. Orwell admits that he does not always
follow them—and of course the last rule gives the reader
explicit permission to violate the rules in certain
circumstances—but it very much makes one wonder what the point
of "rules" are if they are made to be broken so regularly.

Let's look at each of these six rules:

# 1. Never use a metaphor, simile, or other figure of speech which you are used to seeing in print.

Orwell's complaints about metaphor are twofold: one, that overuse
of these metaphors robs them of their meaning, and two, that
they can become divorced from their original metaphorical meaning
and become abstract phrases.

The first objection presupposes that meaning is necessarily
diminished through use, and in some cases, this may very well
be true. The impact of a word like _fuck_ is of course lessened
if it is used incessantly, and phrases that necessarily connote
some kind of unusualness or uniqueness—like _Achilles' Heel_,
which connotes a unique but absolute weakness—can suffer a
semantic shift such that they start to connote a less unique
situation.

Those, however, are special cases. In general, meaning is not a
quantity that diminishes with use—it is a quality that shifts,
and no number of essays can prevent metaphors or even just words
from shifting their meanings over time. This is no more or less
true of figures of speech than it is of words: who today uses
the word 'silly' to mean "blessed", or the word 'bonanza' to
mean "fair weather at sea"[^bonanza]?

[^bonanza]: For that matter, who today uses the word 'bonanza'?

As for the larger point: the reason that metaphors are useful
is because they can take a situation and explicate it via
similarity. A writer shouldn't overuse them, but on the other
hand, why avoid a common metaphor if it is appropriate to the
situation at hand? I could attempt to come up with an uncommon
metaphor to describe the "flow of money"—money is not a liquid
and does not flow!—but why do this when I could 
