The first two paras in what I've quoted are frequently asserted by 4e players as well, only with "adventuring" in place of combat.
I think, in this thread, it was @
S'mon who said that a high level wizard has done a lot of adventuring, and therefore gets better at it (including +15 to open doors). And I made the point that I think the 4e designers were motivated not by ignorance of lopsided builds, but by a view that they wanted the rules to exclue them in order to make adventures work.
I understand what you mean, and I was attempting to do is my explain my opinion that it changes for me when you open up from a skillset like "combat" to a much broader "adventuring". Like any stereotype, the broader/simpler the abstraction, the more vulnerable to scrutiny. At some point, it breaks for someone somewhere.
For one person, maybe the breaking limit is when PCs become better at skill checks outside the adventuring sphere. For a gritty player, maybe it's the wizard who is always hanging at the back and pew-pew-ing magic from a distance, and therefore shouldn't gain base attack bonuses to melee. For a deep immersionist, it's the PC who put 5 skill points into Climbing halfway throught the adventure but didn't actually do any climbing. (I'm just using these as theoretical examples that you can't please everyone, not as examples of what I think are the most endemic issues).
It's one thing to have my scrawny wizard adventuring with Conan. But what is my scrawny wizard doing hanging out with Heracles in the heavens, in danger of getting squashed by any wandering inhabitant?
If we're going with the scrawny wizard archetype and not Gandalf with a sword, then I picture the scrawny wizard as being powered by uber-magic, but underneath that magic, he's still an ordinary man, particularily with Conan sword-and-sorcery fiction.
If he gets into heaven with Heracles, there perhaps he is a mere mortal but still capable of incredible magic, like a sci-fi soldier in a a supersuit and plasma weapons. Or he made it into the heavens by undergoing some sort of arcane apotheosis, becoming 'one' with his magic. I'm not sure -- I haven't thought that far.
If what concerns you is that a simulationist game breaks at Epic level (or even Paragon level), the "Lore" edition can have a toggle on the maximum PC level, like E6 does.
Which is fine as far as it goes, but I think raises the issue of "why will those players switch from what they're playing?" And this is where I think the sandboxing idea has some merit.
So for yourself, and please correct me if I'm wrong, the breaking limit of simulation for you is a middle-ground between gonzo-super-heroic fantasy and gritty fantasy, is that correct? That it is incoherent because it tries unsuccessfully to merge gritty and gonzo?
Yet 3E/PF is considered a simulationist game by many. I know you don't. Myself, I am ambivalent on that. So we know simulationism is very subjective.
Thus recognizing that simulationism is so inherently subjective, I think a simulationist system might a) choose a specific fiction from which to build the rules, or b) have toggles to allow the group to set the fiction they consider to be simulationist and immersive and provide the appropriate tools.
If you choose (a), then clearly, the problem is not that everyone likes the same fiction (whatever drove people from 1E or 2E or 3E). But the entire foundation of the game is built on that narrative, so you either have to tolerate it or play another game. And even if the narrative is extremely compelling (say, a Game of Thrones RPG), it may be too narrow to have mainstream appeal.
But if you choose (b), you have to have an elegant system for adjusting the rules, which makes Mearls and Monte's articles so pertinent for me.