"Flat" design is equally offensive by not demarcating controls as controls, or their state in an intuitive way.
Just as we were finally seeing UI step away from that BS, Apple jumps all the way back into much-scorned, cheesily-excessive skeuomorphism... adding a raft of failed ideas from 20 years ago.
Since this is in contrast to "wildly not flat and full of visual gimmicks": the modern "flat" style has severe (and very stupid) issues, yea. But "flat" has been around for a very long time in touch UI with clear control boundaries - just draw a box around it, maybe give it a background color.
That's better than plain text that just happens to be a hidden control, but text with a background color might just be... text with a background color, for emphasis. Or it's text with a background color, to distinguish it from editable text. A background color does not tell the user that it's a control.
A box around it? Slightly better, but still doesn't convey state. Sure, you can fill it in when it's "on," but that's still guesswork on the part of the user if he arrives to find it filled in already.
Just as we were finally seeing UI step away from that BS, Apple jumps all the way back into much-scorned, cheesily-excessive skeuomorphism... adding a raft of failed ideas from 20 years ago.