An argument could be that Samsung was trying to get people to buy their phones as a way to look like an iPhone owner without having to pay more for a real iPhone than you paid for the 'clone'.
Another argument could be that, by selling inferior wares that look like Apple's stuff, consumers would start to think that Apple's phones are inferior. For example, you meet your friend and spot him with this black phone. In casual talk, he mentions that it isn't as good as it looks. A month later, you are looking for a new phone, and someone shows you an iPhone. Not having looked closely at your friend's phone, you may be steered away from buying an iPhone.
A third argument is that Apple spends a lot of effort and money to make their devices appear hip/cool/attractive. A clone-maker benefits from Apple's work. He does not need to advertise its wares as much as someone who makes original wares would.
Neither of these arguments are new; they are also used when people sell e.g. Bolex watches that look like those of that other brand.
I don't see how the first two arguments could apply to this case, where UI is discussed. Products being confused is a result of their (dis)similar external appearance, not their UI.
Another argument could be that, by selling inferior wares that look like Apple's stuff, consumers would start to think that Apple's phones are inferior. For example, you meet your friend and spot him with this black phone. In casual talk, he mentions that it isn't as good as it looks. A month later, you are looking for a new phone, and someone shows you an iPhone. Not having looked closely at your friend's phone, you may be steered away from buying an iPhone.
A third argument is that Apple spends a lot of effort and money to make their devices appear hip/cool/attractive. A clone-maker benefits from Apple's work. He does not need to advertise its wares as much as someone who makes original wares would.
Neither of these arguments are new; they are also used when people sell e.g. Bolex watches that look like those of that other brand.