One can, as the song goes, "accentuate the positive" -- but only so much. Meanwhile, "eliminate the negative" is practical advice for neither speaking nor writing. In no way can one not use "not" (see, for example, Software Does Not Fail). Indeed...
In any sentence in which it appears, "not" is the most important word....which is precisely why I don't use "n't." Well, maybe I do every once in awhile. Like for the title of this book.
See here: suffixed to the word "do,"
the adverb "n't"
has the power to modify both the pronunciation and
spelling of the root
verb. Same for "shall" and "will." That's
not shabby. Everywhere else, though, "n't"
doesn't, so I shan't,
thus assuring that, suffixed and apostrophed, "n't"
won't get underlooked
by listeners and readers.
Every sentence in a message from my brother Alan, a noted playwright, was polluted with n'ts and concluded with "[I] won't re-write any of my scripts on the basis of your article."
By happenstance, my brother's rejection
called to mind
the puzzle "Syllables
of Recorded Time"
and inspired a few observations...
Suffixed to "will" and "can" and "do," n't saves a syllable...