I love the trend towards restraint and away from the excesses of Calendar et. al., and agree with Gruber that effects can and should be used where they can enhance usability.
But I don’t buy the argument that skeuomorphism was used to cover up for low res displays. In fact, the whole reason people went apeshit with it in 2008 and not 1995 or 2000 was that screens finally had enough resolution to make it look acceptable.
Gruber’s last paragraph:
"Something like Letterpress doesn’t look bad on sub-retina displays (I play on my iPad Mini frequently), but there’s no wow to it. It’s just there, true to itself, and true to the mediocrity of the display. But on retina displays, simple, pure, true designs like Letterpress have a bracing effect …."
Swap in “Calendar’s rich corinthian leather” for “Letterpress” and that makes even more sense. “Flat” design has always been a good option on low-res displays (at first, it was the ONLY option!). The difference today is that we’ve finally had enough of the faux textures to really appreciate flat in contrast.