The explanation isn't for why people care about politics per se, but that we care so deeply for politics that we respond to adversity much, much harsher in political environments than in others. Or, our reactions are disproportionate to the actual risks involved in it. People become angry when discussing if something should be privatized or if taxes should be raised. If one believes that there is some general policies that most benefit from, it's really bad to become angry at those whom you really should be allies with.

That's different from what I'm used to here in Sweden. For most people here it's accepted to not vote - if you put a blank vote in the ballot box. Even though most vote (more than 80%) it's not considered bad to not have a political opinion, you can just say you don't understand enough. In the bad all old days it seems that there was something of a taboo to ask others what they voted for, which made it easy to skip discussing politics.