Let me start by saying Samsung didn't copy Apple.

That out of the way, there is simple no way that "Apple fanbois" could make a market for Apple, people have selected the iPhone in the numbers they have because they like the iPhone. The same was true for the iPod, you simply can't explain the popularity of that device by citing only the early adopters that first embraced the new device. Early adopters lead the curve and the rest follow, that the reason companies like Apple work so hard to court them.

effect of the fact that Apple had access to a mass of brainwashed fanbois that will buy anything with an Apple logo, which provided them with both the funding and the opportunity to target the deep-pocketed early-adopter market.

But in a world where Apple didn't exist, Samsung would have shipped the Galaxy family of products around the same time as they eventually did - and they would have looked just as they do, too. Any resemblance in design between Sammy's products and Apple's is due to convergent evolution: it is simply less efficient, if not thoroughly impossible, to make a smartphone or a tablet that doesn't feature that shape, that button, that grid of icons in those specific colors - or even one that doesn't ship in that type of box.

But this is simply not true, Samsung and LG were working on a variety of different devices, advanced devices with mobile TV for Asia and basic feature phones in a variety of designs, but primarily flipphones and Nokia-like candybars. The same is true of Motorola which was trying to retain the marketshare they were quickly losing with the Razr and Razr-like devices.
I'm sure Samsung had something like the iPhone in development, running one of a variety of underpowered home grown OSs or maybe Symbian. I'm sure that they had something like the devices they had been building with Windows Mobile. I'm sure they were slowly getting to a device resembling in a number of superficial ways the iPhone. But they did not have an iPhone in development, a device with an OS designed to run fully native applications, a device embracing the "real web." We can see this in the devices that were out at the time of the iPhone being announced, the web browsers were these limited "mobile web" browsers designed for stuff like "compact HTML" but mostly running WAP sites.
I will agree with you on the shape, and an Apple design patent claiming ownership of any rectanglular device with a screen is truely absurd. On the other hand, the Apple earpiece was a unique design element that was very quickly copied by almost every phone out there after the iPhone was shown to the world. I rember browsing Engadget and BGR in the months after and seeing just the tops of the product shots, almost all of them featured the Apple earpiece design, even in feature phones and flip phones.

The four icons below the screen is not as much of an innovation as Apple claims, and certainly not a unique look and feel element of the iPhone. The four main applications were represented by physical buttons on the Palm devices, located directly below the screen. (Apple made some subsitutions for the modern mobile device and to tie the iPhone back to the iPod.) The application grid was present on the Palm as well. (And arguably can trace it's history to Apple's own Newton, but that's irrelevent to it's status as prior art and commonly accepted design.) But you claim that these are the only possible choices as far as design and color? I can't see that. I would suggest that the iPhone followed the trend towards more colorful and thematic interfaces started by third-party software for the Palm OS and Windows Mobile devices and possibly Symbian.

As far as timing, the iPhone caught other manufactures unawares, pushed the CPU speed forward (indirectly, the original iPhone was using an outdated CPU but one on Samsung's roadmap meaning that Apple could move to the next version of that chip without a full redesign of the circuit layout), and pushed the carriers towards Android. While Motorola had already come out claming they were going to focus on Linux their actions did not match that statement. HTC was one of Microsoft's biggest OEMs before they took a chance with Android on the G1. LG had a prototype "Prada" device, the closest to the iPhone that had been publically shown, but it may have been rushed to coincide with the iPhone.