The plain fact is that most of us are smart.
Yea... no!
The majority of people these days can't think their way out of a paper bag.
In that light, I think Tim Cook shouldn't have made his remark. He knows the historical timing of these reports, so he knew one would soon be released on the Apple Watch. And he was probably afraid because he knows the component costs are lower on the Watch. But it makes him sound almost like a liar. At least some of the previous parts cost estimates must have been close - even if only by chance.
Well, I'm sure these cost estimates are kinda, sorta somewhere in the ball park. But, since the parts aren't actually all available for purchase, and don't count manufacturing costs and techniques accurately, Tim was probably right in saying what he said. These are just wild guesses that maybe, possibly give some insight into component costs.
But, they are also kind of goofy, because they are pretty much irrelevant. And that, I'd guess, is maybe what ultimately caused Tim to make the comment. I'd probably just have rolled my eyes and laughed, but that's why I'm not CEO of Apple.

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I don't mind high profit margins if the product is excellent (which the Apple Watch is not) and if people are willing to pay. It's when you sacrifice function, performance, and customer satisfaction in favor of increasing profit margin (ie. bean-counting) is where the problems is, and this is what Tim Cook does (e.g., soldered memory, crippled products, shell-game pricing schemes, etc.).
Huh? The Apple Watch isn't excellent? Useless maybe (the whole product category is), but it's easily the best in the category (again).
And, I like the current direction of Apple's products for the most part... you just have to think ahead a bit. My more recent Apple purchases have been extremely reliable and there is no way they'd be as small and ergonomic, etc. if they had to have user-servicable parts and doors, etc. With the quality of components they are now using, and lack of moving parts, there just isn't much need for that anymore.
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You sound like my economics teacher in college. The problem is that under their systems Apple should be out of business and all of their competitors should be the richest companies in the land. I would sit in class and marvel at how upside down it all sounded and how in most chapters Apple was doing the opposite. This brought me to a realization. My business classes were being taught by people who never made it in business. This could explain the high percentage of business failures. When you learn the policies of those who couldn't make it work themselves, you doom yourself to failure. That's why the founders of the largest tech companies in the world all dropped out of school.
While I'd never discount a good education, there is a good bit of truth in what you're saying.
First, while the knowledge of the *science* of economics has never been at a higher point, economics is also part of the humanities... and modern economics has that people aspect almost entirely wrong.
And second, a lot of the tech industry hasn't even been run according to sound economic principals (or even good common sense)... it's just been utter stupidity. That's a good part of the reason Apple had it's dark years under idiot CEOs (well that, and that companies like Microsoft were cheating (i.e.: doing illegal stuff)).
I think the reason some of these people have been so successful is that they haven't necessarily learned all the stupidity and just ran off of common sense for at least some aspects of their businesses. I've worked most of my life in IT, and always have to laugh when I hear some company say they are going to install xyz software because some big company uses it... actually, that's all the more reason to question it!!!