I am a huge fan of Tiger's and respect immensely his game, focus and competitiveness, but I really think he has been winning in spite of his new swing.
I'm not sure what he gained out of the changes. With the upright Harmon swing he seemed much more accurate and longer.
Now, he's far more erratic off the tee and with his irons and he's nowhere near as long in comparison to the rest of the field. I know he was coming off injury at the Masters, but Mickelson was bombing it past him. Additionally, I think it's at least debatable whether the more rounded swing is harder on his knee, since his most serious problems occurred post-change.
I remember Johnny Miller opining when Tiger went to the more rounded approach that the more rounded swing would create more sideways misses, which seems to be spot on.
Obviously Tiger is one of the great competitors in history of any sport, but here I think his ego really worked against him. It seems he got too caught up with the credit Harmon was getting and wanted to show everyone that he "owns his swing." I think the more criticism he gets the more stubborn he becomes. If he were to go back to Harmon's swing now, he'd be admitting he made a mistake. Again like Miller says "great golfers tend to think they know the name of the unknown soldier," and don't like to admit when they're wrong.
Obviously Tiger is still the best golfer, but his success post-Harmon is really a tribute to his otherworldly focus and determination. Between the ears he has it all over the field. If he ditches the Haney swing, he'll return to his early form no doubt.