Probably because it's hard to prove, it can become a big and arguably irrelevant distraction, and it opens up the possibility for an endless line of "this was inspired by that" from both sides. It's not too difficult to argue that everything was inspired by everything else all the way back to the stone age. The crux of this case is the question of whether Samsung has been copying Apple. Whether Apple copied someone else is arguably irrelevant. Sony can sue Apple themselves if they really think that's true.

I do understand that Apple may very well have lifted ideas from Sony and others and I have to admit that it is a valid argument. I'm only speculating as to why the judge decided not to admit the "inspired by Sony" evidence. In my eyes I can see my reasoning as being realistic though I'm not sure if it's right or wrong.

As an aside, and really, beyond the scope of the law, if you look at this from a human perspective and ignore the black and white aspects of the law, I think it's pretty obvious that Samsung has been imitating Apple's designs. Forget who worked on touch screens first and forget who first created a brick style phone with the same kind of interface because I really think that's irrelevant. Lots of phones look and function like the iPhone and the iPhone looks and functions like lots of other phones but what's really important here are the details of the design and not the generalities. If you look at Samsung's phones that came out after the iPhone you see what seems to be an attempt to piggyback off the iPhones success and maybe even confuse consumers into buying the wrong phone or making them think, as they often do, "it's basically the same thing". The minor details of Samsung's phones and tablets like the middle "home" button, the radius of the corners, the thickness, and even their packaging are so similar that if you took the logos off the phones and/or boxes its easy for even an informed consumer to mistake the two from ten feet away. I've seen tons of touchscreen phones both close up ans far away and most of the time it's not difficult at all to tell an iPhone apart from the others despite the similarities they all share (that's even without my glasses on). But if you take the Samsung phones and tablets in question and compare only those then it's quite easy to not be able to tell the difference until you're actually close enough to hold it up to your face. Legally, that's probably not important but practically that's the real issue. Even if Samsung had come out with touchscreen phones in a style like the iPhone ten years before Apple it shouldn't matter because Samsung began making what really look like clones of the iPhone only after Apple put the iPhone out.

I know if I argued this in court I'd be on shaky ground but I'm not arguing the legalities. I'm looking at this through the eyes of a real person. Touch screens, sing button or multi-button, rounded corners, etc. don't matter. When you see a copy of something else, you know it. I think whether Apple wins or loses the case it doesn't matter nor will it settle the argument. People who have seen the phones and tablets in question all know and see what happened and with so many touchscreen devices out there that are obviously very easy to differentiate from the iDevices, it can't be a coincidence that two companies were working on designs so similar right down to the tiniest details at around the same time. I think Occam's Razor applies here. The simplest explanation is that lots of companies were working on similar designs around the same time but when Apple's took off Samsung purposely started designing their devices to look like Apple's to piggy-back off their success. The result? Moms who always buy the wrong thing bought a Samsung phone or tablet as Christmas gifts because "they're basically the same thing, right?" and Apple sued Samsung.