Seems you have a case of a selective memory because the case in question had some more arguments than round corners. It's intellectual dishonest to reduce it to only that.
I find it hard to believe that they got the patent D670,286 approved in the first place. The 'some more' arguments you are talking about were equally insane. Icons arranged in a rectangular grid? How else are you supposed to arrange them? Flat screen, button at the center? Are these patent-worthy? If you notice, Apple themselves copied a lot before and after that incident. For example, camera at the back, browser in a phone, icons you can touch (or touchscreen itself?), etc. and the list goes on - so it's not that they started everything from scratch. It's just that there was either no patent at that time which covered such stupid things, or even if there was, they didn't want to use them offensively. Yes, they had Samsung's internal document which talked about copying their elements, but then they should have talked about only those points. If one of the major (and first) points of argument is that it had similar rounded rectangles and flat screen, people are definitely going to mock them, and remember it "selectively".
Samsung was being caught having a 155 manual (http://www.theverge.com/2012/8/8/3227289/samsung-apple-ux-ui...) of how to copy the iOS UI. That alone is so clear that it's not even funny.
That's a fact the iHaters always seem to left out, but the round corners on the other hand...
I find it very hard to believe they won that case on the pure fact another device had round corners.