Another thought...
Tiger basically admitted that his game sucks, but I think the way he described it touches on something a little more disconcerting on a deeper level. "Vulnerable" has several definitions, but that's the word he chose. And it's an interesting choice of words, because (to me) it hints to something a bit more disconcerting than just a swing flaw.
We've seen him on an off day, many times over. We've seen him miss fairways by 40-50 yards, we've seen him airmail greens with a wedge, we've seen him 3-putt numerous occasions and still remain reasonably competitive all the while. At no point during any of that time did we hear the word "vulnerable." What we've not seen very much of however is the green-side butchery that pretty much shocked everyone the last event he played, over a year ago... his sudden inability to hit a chip or pitch shot cleanly from a tight fairway lie, or the sudden lateral shot coming from a LW to a short-sided hole location.
It's pretty obvious that at that level there's a point when the ability to remain competitive requires those type of delicate shots to at least be considered... when a straight-forward bump-n-run ain't an option to salvage a par. Even the more average players on tour have at least a base level of confidence and reasonable success rate in those close-quarter situations, otherwise they'd struggle to even be average players, especially considering that the average tour pro is only going to find give or take 65% of the greens in regulation during a typical tournament round.
Be it the chipping yips, the shanks, what have you - he's clearly nowhere near overcoming the lack of confidence, and that's mental. That's where the term "vulnerable" comes in. He's vulnerable anytime he misses a green. If he only missed one green per round - who cares. But he's not gonna hit more than 13 greens per round. It's those 5+ missed greens per round that reveal the chink in the armor... the lowest of lows, the 20-handicap competing with the best players in the world in the area of the game that matters most at that level. And to make matters infinitely worse - it's a humiliating experience. Even the worst players on tour can reasonably execute a short-game shot without thinning it, hitting it fat, or shanking it.
Vulnerable? You bet. When you've spent most of your career being this fearless, dominant player and suddenly you're left with no other choice but to come clean and openly admit that you no longer have the one performance quality that separated you from everyone else - your ability to get the ball in the hole - you've essentially stopped just short of officially stating that your competitive playing days are over.