When you say that "there are two legal systems" Wouter" (forgetting for the sake of clarification on this point, Islam, China, Russia, and several other sovereign state and religious systems), the French and the Anglo Saxon systems, and that most countries follow one or the other, I have to add here that, although the US system may have "originally" been based on the Anglo Saxon system before the US constitution and their bill of rights were written, from that point on in "legal" time there has been one very important divergence that has created the grounds for this ability for "personal litigation" to grow within the US system at a far greater rate than throughout other countries who’s systems are also based on the "British" system. Within the US system the word "JUSTICE" appears, and that JUSTICE can be sought by any citizen of the USA wherever/whenever that citizen considers that they have been unjustly "set upon". As a consequence that legal system has been debating and exploring all the connotations of the effect of that concept ever since the formation of the USA as a sovereign state. As far as I am aware, in no other legal system based on the "Westminster" system does the written word "JUSTICE" even appear! All other Westminster systems proclaim to be the official organ to "UPHOLD and ADMINISTER" the LAW -vastly different from "JUSTICE". This variance creates a vast gulf between the practicing US system and the Westminster system used by many other countries.
Mind you the French system was created by a group of blood thirsty “revolutionaries" who liked to go around cutting off the heads of anyone who they thought was a “POLITICAL” enemy, so does any one image that JUSTICE was foremost in the minds of the people who wrote the French legal code?