As one of
Shadows of Europe authors, I happen to have an opinion of the subject. Note that what follows is not neccessarily the thoughts that were behind SoE - first because a number of other people had their input as well, and also because I also have given this a lot of afterthoughts since. If I was to write the book nowadays and alone, it would certainly be very different.
The first thing is that wordcount was one big constraint. It was a deliberate choice to have each chapter focus on what makes the country
deviates from the Shadowrun standard. So you don't get constant reminder that the ten largest megacorporations worldwide have a presence in most countries, that the Matrix is pretty much the same everywhere, that orks and trolls face racism, that magic and cyberware appliances are common enough. That gets mention only when it's not. Ultimately, the book may effectively read like one long collection of signs that all read "This is different here."
The very concept of "Shadows of" sourcebooks requires each country to differ in some way. Which is not that easy. Once you settled that the book is not going to enter into the specifics of parliamentary dynamics, military order of battle or major cities precise street layouts, European countries tend to be strikingly similar. And that's not specific to Europe. Take a look for instance at Athaskan, Aleut, Tsimshian and Algonkin-Manitou to see how they differ. As locations, they're very similar. I don't think SR ever brought anything that would make running a R&D lab in Winnipeg different from running one in Anchorage. Those countries just happen to have different ongoing plots. And there can be a fine line between writing a location with plots and a mere list of generic plot hooks that could take place just anywhere else. A good location should actually allow the GM to take any generic plot hook and make it different by the sole fact it will took place there.
All of that can be problematic in a cyberpunk setting where globalization is a key concept. By itself, the cyberpunk genre is fairly closed. It's about large megalopolis with global corporations, widespread violence and ethnic criminal syndicates. You had Seattle as the enclave sprawl, Denver as the divided sprawl, San Francisco as the occupied sprawl and Manhattan as a the panopticon sprawl. Right. Now those tropes already got used, how ones makes a cyberpunk version of Baltimore, London or Moscow is nowhere near trivial, let alone Memphis, Cardiff or Archangelsk. Among other things, it worth noting that urban violence has a different feel in countries where firearms circulation is much more restricted than in North America.
Shadowrun does add hermetic mages, shamans, and dragons. Hermetism is just as globalized. Shamans and dragons, on the other hand, are defined by coming from another place or another epoch
that is not cyberpunk. Shadowrun amerindian shamans - or elven nations, for that matter - come into the setting with a good third of North America that is completely alien to the cyberpunk genre. It's not random chance that earlier Shadowrun sourcebooks covered only a set of UCAS, CAS and Californian
cities while the Native American Nations and Tir Tairngire were covered as
countries. It's really difficult to give the cyberpunk treatment to a nation as a whole. In no small part because what makes a nation is the local culture and the local government, two things the cyberpunk seeks to erase.
Still, there's some room to work with. National corporations based on existing ones, local crime syndicates, and dragons, critters and magical traditions based on local lores. But introducing new corporations, new dragons and new magic for each and every country was frowned upon.
Regarding France specifically, it was felt that being against whatever come from North America (corporate extraterritoriality) or Great Britain (cyberware) should be a central element of French identity. The celtic angle was already taken by both United Kingdom and Tir na nOg, the various connection to Africa were also significant element in Portugal and Spain, the Mediterranean crime scene was (obviously) primarily Italian... As a side note, French restrictions on megacorporations were supposed to be mostly administrative hassle that comes nowhere near CAS' ERLA investigations or Pueblo or Tir Tairngire sanctions and outright ban against some megacorporations.
That explains a lot, like the flat-out refusal to follow along with the overall metaplots, it seems.
I wouldn't call that a refusal, because that would assume there were any overall metaplots to start with.
Shadows of Europe was designed between 2001 and 2003. The "overall plot" at that point, was
Year of the Comet and FASA shutting down.
YotC was about events in Denver, Japan, California, Yucatan, Philippines... The only thing that could possibly connect to Europe were SURGE and shedim because they were occuring worldwide. Yes,
SoE did not follow up on those, but neither did
Shadows of North America or
Shadows of Asia (in no small part because SURGE was considered a minor event, and because playing shedim straight would completely disrupt the setting). By the time
Threats 2 was released and (re)introduced new plots,
SoE was well on its way (causing some late rewriting regarding templars for instance).