AbdulAlhazred
Legend
Yep.
This is certainly the case in RM, and mostly the case in BW.
I agree with your last paragraph in particular. You can see it in some of the posts on that old thread about bear-taming and water weirds that I linked to earlier. Complaints about the manner in which DCs are set and actions adjudicate end up being complaints about things being too easy, or not easy enough. It's a concern about challenge and "neutrality", not about simulation or the fiction at all!
Yeah, I'm probably overstating it a BIT when I say "nobody ever knows anything about", but we still don't know MUCH. I mean, for instance, in a real melee combat what's the ratio of attempted attacks to successful damage dealing blows? How effective are defensive tactics? What happens if an enemy 'goes kamikaze' what's his chance of landing a blow in that case? These are only a tiny fraction of the questions, and nobody has even the slightest objective evidence for any given answer. The questions often don't even have objective answers because it depends on exactly how you imagine the abstraction working. Often games don't even have a coherent idea of what the abstraction is exactly. D&D is especially guilty of this, HP and AC are notoriously slippery concepts.
About the best we can hope for is that people might be able to classify things as "easy" or "hard", but even then those are highly subjective judgments based largely on what we ourselves happen to be good at, what we THINK we know, but often don't, etc. IMHO most of what people call objective DCs are just about worthless as actual predictors of how something might go in the real world, and as already stated if it isn't objectively drawn from real-life than it logically must simply be invented and is just representing some other agenda.
I feel the same way about claims that you can 'design a realistic simulation of a world', its just utterly impossible. With our greatest supercomputers we can't even determine what the climate of said world would be. Its all DM fiat (say it like "its turtles, it just turtles all the way down").