I'll go with your second reason. They don't have to. The cables stand or fall on their own. As do other products whose evaluation relies on sensory perception like colognes, food, art, and fabric softener. To some there is no appreciation for the subtle differences. To others it's a world of difference. Audio is no different. This talk of rampant placebo and obligatory proof is obsessive and, frankly, pompous. Why should the cable companies listen to you?