I'm of course not familiar with the specific mindsets and the history of this decision, but I want to share a bit of cultural perspective from Germany that is so far not really considered in this comment section: Germany is very, very keen on preventing powerful entities from acting outside of regulation and similarly, if not more, on preventing a single entity to get in control of everything. This is largely due to…
Germany is obviously somewhat keen on letting single entities get control of everything, as the EU is in many ways an extension primarily of Germany, and the closest entity I'm aware of that could be said to be doing just that. I'd also like to mention that certain entities operating outside of the state are precisely the sort of thing that can prevent the sort of tyranny that Germany enacted during the 20th century.…
This is in direct contradiction to your previous paragraph, unless such a system is inherently decentralized, and not controlled by a single entity (such as FB).