I think this belief that form factor comes first or somehow dictates component use is a common misconception (doesn't make it a dumb one).

Apple believes that design is essentially three things: form factor + hardware inside form factor + software. The three have to play together seamlessly for the overall design to be good. We can debate on how effective they are at this, but that is what Apple believes. Steve Jobs talked about the interplay of hardware and software many times.

Steve Jobs also frequently discussed compromises. He believed that consumers paid Apple to make decisions about what was useful and what wasn't. So including Flash in iOS would have meant that users could watch all web video (only 25% at launch!), but they looked at the stability and the battery life and made the decision that, no, Flash was not worth it. So Apple believes in tradeoffs.

Sometimes these tradeoffs are at the cost of the aesthetic. For example the black plastic on the back of the original iPhone, or the black plastic used on the entire iPhone 3G when they wanted to increase margins and go for market share. This is design. This is a company making tradeoffs.

Sometimes the tradeoffs do come to preserve the form factor. I struggle to type on my iPhone, but I was so quick on my BlackBerry that the software lagged behind me. But Apple made the tradeoff.

The antennae on the iPhone 4 is a great example of Apple design. It's accomplishing so much. It means there's no need for black plastic on the device, so the aesthetic is improved. It also provides the structural rigidity for the device, which means they can make it feel super sturdy (love Samsung's aesthetic, but if you hold an iPhone 5 and a Galaxy, there's a real difference to the feel). That sort of outcome isn't the product of a guy in a turtle neck with Auto CAD putting lens flares on everything. That's serious design.

Jony Ive talked a lot about the process for making the MacBook Air. They wanted to build a fast, ultraportable computer without making it one of those shitty 9" Taiwanese pieces of crap. So they had to work with Intel to build a 60% smaller Merom. Because they didn't want to compromise the internal hardware by shipping a slow processor. They had to develop Unibody so they could strip out internal fixtures that would add weight and reduce the structural integrity of the product. Commitment to the aesthetic.

You've cited (it's cited, btw, not sighted) the iMac. Apple wanted to make it thinner and lighter. At the same time they wanted to ship better components inside it. So they had to keep the space inside the same size or make it bigger, or they weren't going to be able to ship the product. So they spent time developing ways to make it thinner and more aesthetically appealing without compromising the hardware components. In this instance I'd argue that deference to the hardware components came first. Much like the MacBook Air, where so much of the work went into developing a tiny logic board so the device could be full powered.

tl;dr Apple makes tradeoffs on behalf of consumers.

> Hence why apple makes the products they do

A quickie on this: hence why is never correct. Just use hence.