To be fair, Apple would probably let someone get away with a rectangular screen if they put a huge unnecessary border around it, or sold it smeared in excrement, or had razor-sharp corners that maimed anyone who tried to pick it up, or did something other than the blindingly obvious things most people would do to make something look nice.
Jobs/Ives/etc did (collectively, and in whatever order decisions were made) decide to make tech stuff which looked nice to many and was aspirational, rather than just functional.
That decision paid off, and they reaped the rewards, but it's not as if they invented the concept of 'nice'.
Once other people start making nice tech stuff as well, it's not at all obvious that there should be much that should be restricted, beyond actual passing-off.
If stuff is white or black or some version of silver, it's going to end up looking a fair bit like something else of a similar shape which is, the way a lot of silver/grey modern cars aren't always too easy to distinguish from a glance - there are practical limits on how different they could look, and it's only really things which are actively different from the general shape (like a lot higher window-line) tat tend to be distinctive.
If people are going to go for unobtrusive and subtle designs, they're likely to look fairly similar.
Biting the hand that feeds IT
