That's a good scene but it not really true. You just can't reveal to students that you have entered a grade based on anticipation of the quality of their works. Frankly, entering all D's in the final grades at the beginning of the semester would save me a few valuable moments during busy finals week.
Shhhhh, don't tell them how we roll. :) But really: after a few assignments, it does get predictable. How often does someone (without cheating) suddenly jump from a D-level to a B or A?I'm going to give everyone F's & tell them they have to prove to me that they don't deserve those. That will motivate this generation, I'm sure of it.
There are days when I think is how it all might fade to black: students simply stop doing work, and professors, unable to play puppet-master to every one of them, have nothing to work with. I suppose that's the view of someone who assigns reading and papers; lecturing and multiple-choice tests could probably go on for quite a while, especially if it becomes accepted to record the lectures and give students the option of viewing them online (otherwise known as playing them on some tab on the laptop while doing a dozen other things).
At that point I think Cynic's solution is going to be the way to go. I've had semesters that were almost like that, and my gen-ed course always has a significant minority of students who can't be bothered to do the homework -- even though I point out that the points lost thereby will probably mean they will fail.