Even in the US iPhone is no longer the big dog.
Current US market share for smartphones stands at Android 50%, iPhone 45% and Blackberry and Microsoft Windows phones fighting over the remaining 5%.
Yeah, that's been true for a while, but ... Apple is currently making somewhere around 80 to 90% of ALL the smartphone profits, and while Samsung users sing about all their new 'features', chances are, they'll all be gone by the next release, and the phone you're holding will no longer be supported.
The iPhone, meanwhile, isn't popular because it's expensive, but because it's proven it's dependability for year over year.
While you say authors are merely jumping on a popular bandwagon, showing a character using an iPhone demonstrates, indirectly, that they believe in quality, in doing something the right way, even if it won't produce the quickest buck, and that they're 'reliable'.
What does a character using a Samsung tell readers? That 1) he's cheap, and 2) that it's likely to explode in his pocket and fry his junk!
Specifics make a story feel more 'grounded' in reality, but it also carries certain assumptions that carry over to their characters. Does your detective drive a Ford, or a Maserati, does he date someone 'kinda cute', or someone 'soul-crushingly beautiful'.
If you, as an author, can't think of anything more imaginative than 'he pulled out his phone,' then why should readers trust your story to be very exciting?
The key isn't to avoid specific references, it's knowing when not to overplay it. You drop casual references, but not enough so it's obvious. You mention a specific phone here (the brand isn't that important), you mention his suit, or his date's dress, you mention the restaurant they're dining in, but most of all, you keep mixing it up. Once you've established he uses a sophisticated phone, you drop the references. The reader already knows, so they DON'T need to be reminded. And dumping a dozen brand names in a couple of sentences is a sheer sign that you, the author (I'm speaking generically here), can't afford ANY of those products.
Once again, the key isn't to avoid taking any risks, it's all about not overplaying your hand. You use the hand you're holding, get what you can for it, and then you get out and play a separate hand, rather than continually trying the same old trick, again and again.