It is spelled out right in the Matrix:
Morpheus: The Matrix is a system, Neo. That system is our enemy. But when you're inside, you look around and what do you see? Businessmen, Teachers, Lawyers, Carpenters...the very minds of the people we're trying to save. But until we do, these people are still a part of that system, and that makes them our enemy. You have to understand, most of these people are not ready to be unplugged. And many of them are so innerred, so hopelessly dependent on the system that they will that they will fight to protect it. Are you listening to me, Neo? Or were you looking at the woman in the red dress?
All kinds of people, it doesn't matter how different they are from one another, fall victim to it. You want to save them, to make them see. They are a part of the system and support and allow it and give up freedoms to give it more power and strength. Most people aren't ready to see the reality of what they are trapped in and the lies and disgustingness and filth they have been living in. How fake it is! They are dependant with charities and loans and social security and grants and loans all funded with tax and interest which may or may not be going to it's rightful or said location and/or purpose. They all fight to protect it because they need it even die for it and fight wars for it. "You have to free your mind." You have to do what they tell you that you cannot do. Ah, the woman in the Red Dress. Neo was looking at the eye candy and not listening when people like me try to spell it out for him and 'save' people. The government gives us plenty of what we think we need and want, instead of what we really need. Distraction and smoke and mirrors.