They're clearly hyphens, not dashes, and they're not substitutes for commas, for commas also appear in the text. However, the ubiquitous hyphens are usually found, like those seen above, where no punctuation is needed. We have to guess that the writer just didn't know whether or not to punctuate at those places. The housewife from Teaneck could have told him, but professionals don't consult housewives. His pals, however, must have been equally at a loss.
Punctuation is a cognitive skill of little interest to professionals.
That's a reasonable enough judgment, but Burke pronounced it untrue and detrimental to our efforts in this area. The housewife from Teaneck wanted them to say that the schools should teach writing, but professionals don't think like that. They must expose the producer's underpinnings. No sane teacher of composition would give this illiterate gabble a passing grade, but it satisfied a pack of professionals unto whom we have given our children as hostages. We intend to be destructive.