I know many games do have these kinds of impossibly hard to find easter eggs, but these tend to be larger games with bigger budgets on less of a leash, like Halo, or the Arkham series.
On the other hand, Dark Souls is on a tight leash to get out all the public, expected to be seen content. We know that they went through the sad process where they hit their production deadline with extra content (chimera) they couldn't incorporate and ended up shipping it with the rest of the game.
So, if you are a studio, on a tight deadline from Namco, and you can't even fit in all you plan to have non-secret game actually into the game. Yet for some reason, you force the development team that is already not finishing things to throw in an overly complex puzzle which, (according to the kind of theories we entertain), is near impossible to find and will never be seen.
Just thinking logically here.