No, I read that, but the author presented a viewpoint from the historic example of luggage, cargo, etc. searches and then simply stated the courts disagreed. Expanding on that to talk about why those things are in fact different and not comparable is a salient point, and not something that a reader of the GP comment would necessarily come away with otherwise.
Because the reasons are fairly obvious to everyone here. Smartphones are basically an extension of our brains. They are our eyes, ears, mouths, and memories. Searching a smartphone (and usually copying its contents) is an invasion of privacy far beyond flipping though a ship log or traveler's diary, so that precedent isn't good enough to establish reasonableness.
