James -
First of all, I am not an expert on either Oakmont or Mr. Fownes, so I can't pretend to know his intent. (I've never been a fan of trying to guess intent, but that's another question entirely.)
Keeping that in mind, I will simply say that the rough is bad, but I've seen worse (though maybe not worse than it will be for the Open, in all likelihood). It does often necessitate lob wedges around the green, but in all honesty, the shots are still different from most other courses with rough-surrounded greens, because the greens themselves have so much speed, pitch and contour. I don't think Ogilvy's perceptive comments apply here (they most certainly don't to the course as a whole), but that's obviously just my opinion.
Imho, the main intent of architecture is to promote thoughtful play, and in spite of how one-dimensional it may appear from the diagrams and photos, there are few, if any, courses that require more thought than Oakmont. It might be a different kind of thinking than most are accustomed to, but it most assuredly there. It is not simply hit-it-here-or-else, not even close.