The whole point of using headphones is to not bother other people.
What you want would be defeating the purpose of headphones.
You are very right, that is the reason, but what is the volume for, why isn't the speaker volume on wide open all the time, because there is a need to lower it, why is there a mute button? Because there is a need to mute it so no one hears it. So there are these controls which change for different people doing different things. How about if I was near deaf and needed the head phones but the rest of the room would like to hear the speakers but not on too loud?
This isn't my issue with the computer but I have bad hearing and I have thought about getting some sort of wireless headphone for the tv. That way it could be on just loud enough for the rest of the room yet I could have a "speaker" in my ear that would help me hear it.
These computers have settings MANY, MANY settings that 90% of the users will never need, never know they exist, yet 10% of the users will find them perfect for their needs and change them. We all aren't the same.
Brian