It has some truth to it, but ignores a lot of salient facts in favor of a cute argument (insert Gladwell dig here). Steve Jobs' had many parts to his genius. Tweaking products until they were really finished was one. But I would say the most important (and impressive) part of his genius was holistic thinking . He wasn't a programmer, a hardware engineer, an industrial designer, an advertising copywriter, or an archit…
Also, the use of the word "tweaker" is a stupid rhetorical trick... Can anyone name a single product that Jobs released that had not already been proven in the marketplace by another company, in substantially the same form? I can only think of one: the Newton. And Jobs never made that mistake again. 'Tweaker' sounds perjorative, but in fact that was exactly Jobs' genius: recognizing the design details that others mis…
I'd argue that the Zen Jukebox did not prove that HDD MP3 players could be successful, and that Treos and other smartphones, though proven successful, were not substantially in the same form as an iPhone, and that previous tablets were proven failures and also not substantially in the same form as iPad's.
I think the iPad is really the best example of Jobs' talent being used in a capacity that wasn't just tweaking. Stylus input and finger input are just completely different ways to approach the user interface. An iPad isn't a tweak of previous failed Windows tablets, it's throwing out the basic premise of the machine ("a tablet is just like your computer but in the palm of your hand") and starting from scratch ("what is the purpose of a tablet?").