Thanks, yes, that's the other important point: you can't turn it around and expect a guarantee of success. I believe the original study didn't even claim any magical threshold of hours either - Gladwell probably just introduced that as a literary device: "10000 hours", and the added suggestion of some mystical threshold, make for much better storytelling than "oh you know, on the order of tens of thousands of hours" :)
And then if you add the other caveat too, it becomes too underwhelming to make for inspiring bedtime reading: "on the order of tens of thousands of hours, provided that you were quite great to begin with"!
Yes, too underwhelming to catch on as much as Gladwell's interpretation has. However, it actually makes an important point: even if you're talented, it requires practice to really become an expert.
And then if you add the other caveat too, it becomes too underwhelming to make for inspiring bedtime reading: "on the order of tens of thousands of hours, provided that you were quite great to begin with"!