Why is it obvious that the customer needs to pay for shipping back a defective product / shipping a replacement product? To me, that's not obvious; if it's a hardware fault, the manufacturer better send a replacement including shipping for free, such that customers don't pay a single extra dime over someone who got sent a good product in the first place.
If they establish their is a problem with the device based on the information you gave them, you will get a free replacement as we saw in Maus0728's case that m2017 linked to in this thread. Maus0728 wasn't required to return the faulty product and he still got a new one.
But there are surely situations in which the customer doesn't provide the necessary information, their support team can't be certain of what happened, or the problems with the device might not be covered by the warranty agreement because of the way the HW was used. That's when you might be asked to have it returned and pay the shipping costs. After they inspect the device and find out what happened, you will either get a new one and shipping costs refunded (if you have a valid claim) or you won't.
People often lie or don't tell the whole truth to get what they want.
My HW just stopped working all of a sudden. This is unbelievable. I had it less than a month. What they don't mention is they dropped it in their soft drink and that's why it's dead.