Unless something's state of affairs is less than optimal already, methinks. Mac OS', and frankly, most other designs out there, including the Web, have been subpar since the advent of the 'flat' aesthetic.
Microsoft may have started that, but theirs was a mostly text-based implementation, which served the purpose of legibility. Apple and company followed by stripping their UIs heavily relying on graphics of both the text labels and the graphics themselves. Oversimplification is still an -over.
P.S. As much as I respect Sir Jony, putting him in charge of Apple's UI design instead of the actual expert Forstall was, and doing so out of spite over some internal 'beef', was a 'red flag' already.