[tjogin]

Another example, I'm not sure it qualifies, is that Gruber never liked the brushed metal theme and the inconsistency with which Apple applied it to different applications.

Apple did eventually retire the brushed metal theme and is getting a bit more consistent in the styling of their applications. Still some way to go here, too.

Apple and Gruber has generally diverged in how they think the Apple Human Interface Guidelines (HIG) should be applied. Gruber has called them out for not applying it as consistently as they did in the past.

But regarding the HIG, it seems Gruber has resigned and is now calling the HIG basically defunct.

I think in general, Gruber is not trying to be right/wrong vs Apple, not trying to offer a strong opinion, except in some unusual cases (see: AppStore rejections). Mostly, he is just trying to understand Apple, and to offer his analysis since Apple is famously quiet and other analysts are often clueless as Apple is a bit of an oddball in the corporate world.