If the defining character of "Lore" is that is has 3E style skill points, and therefore permits epic level wizards to be defeated by wooden doors if they haven't memorised a knock spell or brought one along on a scroll, I don't see it's defining feature as "simulatonist/immersive".
I'll skip down to this point. The 3E skill points vs 4E skill points is not my defining character of "Lore", it is one reference point. (I believe I stated as much upthread).
You or I or VB or S'mon or anyone (but especially you, no offense

does not get to decide or justify that high level wizards feeling human again when faced against mundane doors is simulationist or not, either in some absolute sense or as the default fiction for any D&D campaign for any one group.
Just like I agree that 1E clerics only being able to use blunt weapons probably never needed to be the absolute default fiction for every early D&D game (there were other ways to balance out clerics as 2E+ discovered).
You wrote that you think the designers conceived that not every PC might have a +15 bonus to every skill check, but that they "decided not to make a game in which such PCs can be built. (There reasons, I think, were that they thought the existence of such PCs got in the way of smooth encounter design.)" In my ideal version of Lore, the designers do
NOT make that call.
In my ideal version of "Lore", the system empowers the group to decide for themselves how they envision their character, etc.
At this point, you may interject to say that this is exactly what 4E does. I would refute that 4E does so in a way that is not compatible with my playstyle (or more specifically, introduces new kinds of limitations amd problems to substitute the old limitations and flaws). So faced with an intimidating quantity of rules, I chose the skill system as an example.
And so my in ideal "Lore", you do not get to state -- on behalf of the entire game in general -- that high level wizards do not need to feel human again when faced against mundane doors. You do not get to argue if it's simulationist or not, immersive or not, heroic fantasy or not. Rather, we are both using the same ruleset, but it is flexible to accomodate both playstyles and (gasp!) trusts players to make lopsided characters for unsmooth encounters. Say in one variation, skill points, in another variation, 1/2 character level. When we're comparing campaigns, we're not comparing rules per se (because we both have the same rules), but we're comparing different narratives and simulations produced by the same ruleset.
I don't find this particularly simulationist (at least in the purist-for-system sense)
It's simulationist if the group believes in what the mechanics are doing. So D&D may be simultationist for some gamers based on what they've seen in movies, but other gamers who study medieval warfare and compare longsword vs katana damage find it very unsimulationist.
What does it offer to the simulationist-inclined gamer that isn't already offered by a game like HARP?
I thought people have covered why they felt WoTC might consider trying to capture some of that market.
I think @
CrazyJerome was probably onto something upthread when he suggested an alternative basis for setting up alternative editions - sandbox vs situation as the basis for encounter and scenario design.
I'm OK with all that ivory tower theory. I only interjected a few pages back when I felt that 4E gamist/assumptions keep creeping into the theory. If you were on the "Lore" design committee, I would make sure that there is at least one simulationist designer to balance you out.