Quite apart from anything else, with the screen off how would you know which orientation the screen was in !
That would be the point of automatically switching the button functions, you wouldn't have to remember. The top button would always increase volume and the bottom decrease. Or right/left if sideways.
That wouldn't work. Think about it:
- my phone is in my pocket, I want to change the volume
- I pull it out of my pocket
- I reach round with my fingers to adjust the volume, changing the angle to phone is at
Now guess which button is going to do which function...
Or even worse, try and guess exactly which way up the phone is if I choose to adjust the volume when it is in my pocket !
Then take into account what happens if you change the orientation while changing volume. I'm guessing you say you delay the switching the buttons functionality if I currently changing the volume. But for how long ?
It would be a mess.