I've posted my thoughts on this issue
here. I will refer to that post at future occasions, which I predict will happen with some regularity.
I don't disagree with your assertion about powers. I very much think they were written with the idea you stated in mind.
But I hope you don't mind me disagreeing that the drama rather loses it impact when people are blowing off their encounter powers not because it would be a dramatic point in the story, but rather because they can. That is what I experienced. Every single encounter, encounter powers are used whether or not they are needed.
You can say that is not as it should be. But as I said, I found with 4E as it should be is the farthest thing from a 4E players mind as they would rather use every power they can every time they can use it.
And though you seem to have accepted the theory of 4E (which I agree with), versus the actual use of encounter powers, which seems to be the farthest thing from dramatic I've ever seen in a game.
Encounter powers are used every encounter. As I said I have players blowing every encounter power whether it would be dramatic or not. Why? Because 4E encourages them to do so. It encourages the use of encounter powers every encounter. Not just when it would be dramatically interesting to do so, but every single encounter.
Encounter powers are like watching the same action sequence every five minutes. I don't quiet understand how that is good for dramatic tension. I tried to picture it in my head, but after the 10th or so time the fighter had used Serpent Strike or my rogue had used Torturous Strike, the dramatic tension left me.
Now I used to get that sense of drama you are talking about when a wizard had to go from occasionally blasting off a single spell to unloading whole arsenal and a few magic items to turn the tide of a battle. When a priest had to cast a
heal spell to keep the fighter from getting crushed because they knew if he went down the whole party was going to fall like dominoes. Or when the fighter's damage shot up because he just landed an insane crit or cleaved down five enemies on one powerful swing of his sword. Now the the rogue had trouble with dramatic tension and needed some work. So I'll not try to comment the rogue.
But the other classes had moments of drama that were truly special. Not encounter powers that get used every encounter regardless of whether or not they are necessary, which for me kills the drama of the powers. Which is why my beef is specifically with encounter powers and not dailies or at wills. Dailies do provide a drama boost from my experience as they are used when things go bad and at wills are just a replacement for swinging the sword. But encounter powers, those are drama killers that get used every five minutes. I can't stomach encounter powers.