I fundamentally disagree with many of their reasonings. e.g. tinting the so-called "Content Layer" instead of all the buttons, or demanding "steady state" to be "visually quiet", which is highly subjective. They are optimizing for sheep content vacuums, I mean users, and obedient developers.

As a user, I want color back on my GD buttons!

Also, I don't trust anyone who would wear those outfits.