As stated by Mr. Cage, some people would rather be in the Matrix. Of course none of those people were in Zion, and when you see the population of the last human city you’ll notice when you watch the film a diverse swath of people in Zion of various ethnic backgrounds.
The reason for this, if of course, if you are disenfranchised member of a minority in a western country, or if you live in a country that is “third world” yet has cities (and what a loathsome term that is) imagine if someone like Morpheus offered you the red pill. Perhaps the pitch is different, ala “Human misery is a construct of an oppresive regime, whom you can depose if you join us.” (The question of “is it still terrorism if it’s against machines” is for another post).
Imagine if you are a heroin addict, or a street hustler, or a car-thief and someone offers you a chance to live a world where not only your criminal record is of no consequence, but also where you are relevant as a member of the human resistance. It looks better and better, doesn’t it?
Imagine if you lived in China in 1999, or the Balkans? Places where either terror or fear ran just shy of rampant.
Imagine if someone told you that all that human misery was fake, as a means of ensuring people believe in their reality. You’re entire life and the suffering therein has been structured to ensure that a majority of people continue about their lives without question.
Even more than that, members of Zion logged into the Matrix would be viewed as terrorists. Well it’s the governments job, in a world that’s exactly like ours, to stop terrorism, and in this way-without even knowing- government enforces the will of the Matrix by preventing Zion-based hackers from recruiting more into their number.
Imagine if all the suffering in the world were to equal a certain amount of output of energy. You don’t have to see the people suffer, you don’t have to endure the sight of it. Let’s say that directly torturing one person would power the home of one family. Let’s say the output improved and that torture could power ten homes. Well, a thousand homes would mean torturing 100 people, wouldn’t it? Would you turn a blind eye? Hell, would you even ask where that power comes from? If human suffering defines reality, and reality is the means by which the Matrix gets it power (literally and figuratively) then how much suffering would people accept in order to live.
However, it’s not as though there’s no give and take here. In exchange for power, the Matrix is willing to give people reality in which they have the potential to be content. Not very many are, but the potential is there, and more often than not, the potential too succeed, even in a fake reality, might be enough to keep anyone going.