Try this: just look at the side of a bunch of cars, if you can tell them apart you've got a better eye for this than I do, but ever since the 'windtunnel' took over as a designer I am having a harder and harder time telling cars apart. Plenty of brands have caught on to this and actually share 90%+ of the basic design of the car and concentrate on the interior to differentiate the brands. The biggest difference on the outside is the logo on the hood.
Once physics and usability enter in to the design process the constraints can be such that there will be fewer and fewer options and room to play without impacting those in a negative way.
Design is always a compromise. By going for a minimalist design you remove all of that room so any minimalist design for a device will likely be very much like every other minimalist design.
My point is that once you take away all design and go for minimalist that you can't change it much beyond that without impacting functionality.
The Hofmeister kind is an addition that does not impact functionality, it is the opposite of going for something minimalist. It is a design component specifically added as a signature.
Now if Apple had added a feature that is not relevant to functionality instead of removing a whole pile of stuff that was not relevant and someone copied that particular element they'd have a case imo. As it stands all they've done is taken the device to its logical conclusion. That should not be a protectable configuration.
Once physics and usability enter in to the design process the constraints can be such that there will be fewer and fewer options and room to play without impacting those in a negative way.
Design is always a compromise. By going for a minimalist design you remove all of that room so any minimalist design for a device will likely be very much like every other minimalist design.