A significant number of people just do not care, not only do they not care, they don't even consider whether or not they should care. It's easy to live your entire life disconnected from anyone that would care, for many people they don't even have to intentionally do it. From their perspective they're just doing their job, collecting a paycheck, and living their lives the same as anyone else.

Consider the half of the US population that doesn't vote, not only do they not vote... but most of the time it's not even a system that they think about at all. There are a number of people who barely even know who the candidates in any given election are. You can live your entire life within a very narrow line of sight.