Inflated and vague prose defeats sincerity
All writing is in part a fiction, one of the most subtle and decisive fictions being that the writer is really just talking to the reader in a normal tone of voice. As readers, we are most likely to accept the writer at his or her word when we believe that the words just rolled out of the writer in a natural, unhurried, and relaxed way. We are least likely to put credence in the writer when we suspect that some sort of subterfuge is taking place. This naturalness of language is, of course, all a fiction. For relaxed and natural writing is often achieved through rewriting. That is to say, to achieve what seems natural to the reader requires doing a great deal more than what may seem most natural, the simple spilling of words on the page.
Part of the concern about clutter, especially about telegraphic sound or newfangled punctuation, is that the reader may find the writer affected and, thus, incredible. The same goes for language that seems to draw attention to the wording itself or for inflated language. Of course, inflation has a long and perhaps honorable history in business prose; just look around you. But that same inflation often makes business prose sound insincere, sometimes conniving, usually incredible. One always suspects that a writer of inflated prose is either covering something up, such as a profound lack of knowledge, or evading some dangerous statement. Neither suspicion boosts the reader's inclination to believe.
The most common form of inflation is based on imprecision, whether of language or of thought. If you must be vague, be vague in simple words. For instance, one person might say 'the facility at the conversion of the walls' when he meant 'the thing in the corner' or another might say 'in the very near future' when she meant 'soon.' If you mean something simple and vague, say something simple and vague. Don't swathe your vagueness in the tones of advanced education. Doing so accomplishes nothing; the idea is still vague.
All language is appropriate somewhere, so none of this discussion is aimed at getting you to drop some words or wording forever. This is merely a warning.
The best resolution for vagueness is precision. For instance, the writer who says "A period of unfavorable weather set in . . . " may be fine until that he or she realizes that the period was seven days and the unfavorable quality was rain. If so, "It rained every day for a week . . . " is by far the more preferable. In the same way, the writer who knows that "in the very near future" means "within a year" would do well to say so.