Many swear by them for their alleged utility. Just as many, I suspect, glory in their ability to wrap their expensive devices in rubber protectors that enjoy NFL logos, turquoise sparkles, or even images of their favorite politician.
So, in my constantly dimming mind, I've assumed that there are merely phone-case people and there are tasteful people.
Now, though, my eyes have been opened by consumer psychologist Kit Yarrow.
Speaking to Vox, she painted a far darker picture -- darker than even cockroach art -- of why some people buy phone cases and others don't.
She embraces the idea that Apple and its fellow phone manufacturers want our devices to break down fairly quickly, so that we have to buy another one.
However, when it comes to phone cases, she said the lack of a case sends this message: "I'm above the possibility of damaging my phone, and if I do, no big deal because I can shell out for a new screen."
In essence, then, a naked iPhone says: "I'm loaded." A case-wrapped iPhone says: "This is costing me 60 bucks a month, you know. That's almost as much as I spend on clothes."
Indeed, Yarrow seems to believe that phones are clothes. Or even limbs. As the article quotes her: "The phone really is, for a lot of people, an extension of themselves."
So much so, she insists, that people crave slimness in phones just as they crave slimness in their own bodies.
Is it, though, really a rich versus poor thing?
One could just as easily argue it's a self-confidence versus self-doubt thing.
I know I'm going to drop my phone at some point, so this yes, I know, ugly fat case is merely an expression of my lack of faith in my ability to not be a klutz. I hate myself.
Equally, the lack of an iPhone case could offer other, deeper psychological insights.
For example: I'm the sort of person who casts caution to the winds. I know the world makes no sense, so I get up every day and scream through my window: "Come on world! Give me what you've got! I can take it." I even leave my car open all night, you know.
There's a dangerous tendency these days to divide technology always along rich versus poor lines.
I still haven't quite suppressed my fascination at hearing Google CEO Sundar Pichai claim that Apple's commitment to privacy is somehow elitist. He insisted that privacy should be for everyone and not a "luxury good."
Oh, so that's why Google has never offered it? Because the company is dedicated to the poor and all its phones are cheap? (Clue: they're not.)
Or could it be because Google has made so much money ensuring that both rich and poor don't enjoy any privacy at all?