We hold these truths to be evident…
To many authors, the superiority of plain writing is self-evident. Or, since efficiency is one of plain writing's hallmarks, "evident", without the redundant "self". Plain writing is addressed to the level of a thirteen-year-old — a thirteen-year-old with a peculiar obsession for the encapsulation of each idea in as few words as possible.
This thirteen-year-old does not have much time for nuance. If you temper your opinions with "personally", and "I think", they grow impatient — of course you are writing your thoughts! If they have unrealistic expectations, don't soften the blow with "we can't completely manage that, but…" You need to give it to them straight and accept the consequences.
We can assume they are not impressed by the classics, or at least would prefer them cleaned up to standard: "A rose is… just a rose." "It was the best and the worst of times." "This was an unkind cut." In particular, they are tone-deaf to emphasis and degree. "A violent storm", which to others makes the difference between blown-over plant pots and wrecked property; is to our sullen teenager a pointless pleonasm.
Yet, this brevity-obsessed person is not without a sense of humor. If you write that your lunch was a pita, they would rather ask you why it was such a pain than have you remove ambiguity with the word "bread". Their wide foreign vocabulary, at least when it comes to words for food, is a general redeeming factor. They know, without being reminded, that "chipotle" is a chili; and "gua bao", a bun. Yet, they must be a native speaker of English, or at least have a remarkable capacity for fully comprehending every particle in a sentence without the need for the usual checks. While a speaker of a morphologically isolating language, such as Mandarin, might benefit from the added clarity of explicit time markers such as "already", and "then", our reader picks up on every "ve" and "ed", and mocks any additional words that a more realistic or distracted audience might find helpful.
There is no such person, of course. It does make sense to address certain kinds of writing, such as safety-critical machinery instructions, to a certain reading level, although it would be nice to use more sophisticated measures. And the careless use of tautology can distract or frustrate readers. The problem is that the hairshirt plain style — itself a distortion of the workaday practical style — has been elevated by several writing guides and opinion-shapers into the only correct style¹, and its dictats hang over writers like political slogans. "Less is more." "When in doubt, cut it out." "Kill your darlings." Those who might benefit from this advice ignore it, and blithely pile on cliches like happy proles. Those in the know laugh loudly and publicly, while compulsively checking their own writing for redundancy.
Thankfully, 1984 never happened. The grammar police might arrive unexpected in the small hours, but only in your Twitter feed. We can and should use "redundant" features as necessary for breadth of meaning, emphasis, and comprehensibility, even at the cost of a Flesch-Kincaid point or two. Let's turn off our inner language mavens, and disregard unhelpful advice, especially from fictional thirteen-year-olds. We have a more plausible authority to respect — our global audience.
¹ For a fascinating exposition of an alternative style, and an analysis of the stance and principles that really constitute a writing style, I highly recommend Thomas and Turner's Clear and Simple as the Truth: Writing Classic Prose.