Shmsnh, the reason why the person might have asked is... when I'm in my home office I have my Phone, the desktop PC, and my Xbox One. With ALL three of these devices ONLY recognizing "Hey, Cortana..." it can be a real PITA! I would prefer being able to designate the devices e.g., "Hey Cortana... (for my phone)" "Hey Xbox..." Hey PC..."
Even my Amazon Echo Dot can use a few more "predefined" names besides "Alexa."