Originally posted by kento
it sounds like you're making excuses for flaws in the movie so that you aren't dissapointed with it.
the only people that actually knew that they were in the matrix, were the ones that were told by people not in the matrix... some people had a feeling that something was wrong or whatnot, like morpheus explained to neo, but they never knew it... now that the machines will free people that want to be, i'm sure morpheus and everyone else will tell as many people as they can that they are in the matrix and they should get out and join the real world... and since the machines need the people from the matrix to survive, it all won't work out.
Aside from your initial comment
I do agree slightly.
However, in Revolutions you saw that humans weren't necessary really. the reason it isn't necessary is because the machines could simply place solar panels above the atmosphere to collect an infinite and powerful source of energy.
As you said some have a feeling something else is out there, something more, like they are living in a facade of life. These people with that thirst for the "something more" would be the ones that are freed...but also as you yourself said, not all people are even remotely aware of this possibility.
If there were more that were aware of this possibility then Zion would be overpopulated with people being freed constantly.
Since the system is connected to these people it would be reading and monitoring their thoughts and urges accordingly, and releasing those that have become "aware" of the possibilities that exist.
The system is not going to hand every human the choice per se but rather will go on the electrical impulses that it monitors.
In order for Morpheus to tell as many people as possible then he would have to enter the Matrix once again and begin preaching to these people as though a minister (or whatever you want to call it) and these people are seen as crackpots by the masses and will be shunned or laughed at because the "norm" is to think they are crazy for thinking "outside the box."