Statements starting with 'There are only two kinds of people in this world...' have become a bit of a cliche, but I think the following binary view is still worth considering. The opposition I speak of is between those for whom justice resides in ends and those for whom justice resides in the means. It is an insight that has no doubt been expanded on in depth elsewhere and I hope to do some more research when I have some spare time, but even in its basic form I think it is key to much of the conflict of ideologies.
If it is not immediately apparent, Anarcho-Capitalism is predicated on justice residing in the means used, not the ends, one of it's chief observations being that people hold varying, often incompatible ends. Once this is understood, it is immediately apparent that any ideology that holds the ends as its justification must necessarily be coercive, as the justified end will have to be forced upon those who do not agree with it. This is an essential aspect of collectivism of all types, social conservatives and puritans fall prey to this thinking as much as the run-of-the-mill socialist.
I suspect the majority of people do not base their thinking strictly on one or the other approach, but rather stick to non-coercive means for the most part, whilst turning to coercion for an end they particularly value. Unfortunately in a democracy this means that for any given issue there is always someone who believes the ends justify the means, and they tend to be the ones 'shouting the loudest'.*
*For example these loathesome, subhuman, congenital losers.