In the meanwhile they also somehow managed to file patents for rectangular products with four evenly rounded corners[1]. My kitchen cutting board might fit the bill.
And yet, it's common practice, and it makes quite a sense:
"I think most people don't understand what it means that this is a design patent - it's not the same thing as a "regular" patent (a utility patent). Design patents allow a company to get an exclusive right to the form of a functional object so that a 3rd party can't make a different device with identical appearance (well, not legally at least). Almost every company that puts the time into making a distinctive shape for their devices gets one: Microsoft has one for the Xbox, George Lucas got one for Yoda etc."
Not to mention, if it was so trivial, tons of other companies would have made the exact same design before, not copy it after it was released.
Gee. It's almost as if it's what's inside that matters, and lacking the technology inside the iPad, those other companies had no reason to adopt the corresponding product design.
(Except, of course, in the TV and movie industries, where any number of prop designers did exactly that, decades before Apple.)
[1] https://arstechnica.com/gadgets/2012/11/apple-awarded-design...