NOE strikes are sometimes necessary, say in the instance of a torpedo run, but thats about it. Yes they can be properly executed, but the timing required to do so usually results in the bombers being destroyed anyway.
I'm just going to say the obvious here.
As an escort, your mission isn't to keep the high ground, it isn't to live, it isn't to get kills.
It's to make sure the bombers live no matter if they WALK to the target. Even if you all die trying.
That's really all you are there to do. You are a team and they cannot LIVE without you.
If they die, they fail the mission and so then do you.
but you will do what you will. 
You are correct that an escorts job is to keep the bombers alive and nothing else. It is also true that an escort job is a two way street, and should not be a babysitting job. Escorts make a bombers job easier, but bombers should also do what they can to make the escorts job easier. As you said, they cannot live without us. By going NOE, it makes an escorts job extremely difficult. 9 times out of 10, escorting is nothing more than minimizing the time the enemy has to fire on the bombers. Now we all know that the bombers are going to be shot at. That is a given. An escorts job is to minimize that shooting time. This is done by either engaging the enemy formation before they can attack, or simply forcing them to turn away from a gun run or die. As the battle drags out and both escorts and enemies have taken losses and lost position and speed, it is usually the escorts simply pushing the fighters below the bombers altitude and denying them a good firing solution. By going NOE, the bombers have effectively narrowed the escorts choices to 1. That is to find and engage the enemy formation before they find the bombers. If the enemy find the bombers before the escorts can engage, then it becomes a race to see who can dive to the deck faster and not crash. But what if there is another group of enemies? then they get a free run on NOE bombers from 20-30K, and there is nothing anybody can do about it.
I hope this clears what my squaddie was saying earlier. We don't fly NOE simply because we are protecting our own score and looking for kills.