mahgister,
I do not know anything about value of those cables, but do propose that one of the reasons for that approach is simply business.
Mr. Morrow is in the business of earning money from cable sales. If not, he would have been giving them for free. In this very competitive cable market, just like any other manufacturer, he needs to distance his products from others'. Emphasis on cable burn-in may be that approach.
Not having money-back return policy would make many potential customers skip his offerings so it would not be a good idea. Understandingly, he would be better off with less returns. Offering return policy, but making sure that it is discouraged under the explanation "you need time to settle" or whatever else, could yield multiple benefits.
"Story" (burn-in) with the cable, return policy (not to alienate potential customers), and a few hurdles to skip over while trying to exercise one's right to return, and you may get good sales with less returns. It is not an unusual business/marketing approach even without starting to talk about any real/perceived functionality. In fact, why would he do it any other way?