Why do designers/manufacturers...?

I actually asked that question to two designers of electronics (major designers) --- each were uniform in their response. They both said re: power cords that power cords do not sufficiently contribute to the sound and, as such, they would not raise their costs by way of putting a "better" power cord on their product because it would not enhance the sound. The one designer (extremely well known)said it is an audiophile myth that power cords matter overly --- but that he designs now (like everyone) such that you can put an after market cord on if you desire. he said he does this "because those myths matter in what people are willing to buy... so because they want that flexibility... he would give it to them (even though it matters either not at all in terms of sound/or minimally in terms of sound)."