Why doesn't Samsung go back to building the battery into the door itself?
Say hello the the one and only Samsung phone I've ever owned: the SCH-N330.
The N330 was, as far as I know, one of the most unique phones Samsung ever released. As you can see from the image above, the display actually slid into and out of the device; not quite a slider in the traditional sense, I called it a "pop-up" phone. Two buttons on either side made the display pop up and out of the phone, elongating it for easy talking. The great thing about this feature is it allowed me to have a compact, non-flip phone (I never cared for flip phones) without having to worry about locking the screen, unlocking the screen, or hunting for buttons when answering/hanging up.
Popping the phone up answered calls. Pushing it back down hung them up, and locked the display. The phone was small enough with the display down that it could fit into my change pocket, and long enough when the display was out that the speaker met my ear and the mic was close enough to my mouth that call clarity was unharmed. The phone also bucked the prevailing "cameraphone" trends. This phone was just a phone.
Here's where this phone gets relevant to the modern era. Like many other "dumb phones" of the day, the N330 had a removable battery, attached to a plastic frame. But it never felt at all cheap, at least not to me, no matter the materials. Why? Because the door was fused to the battery itself. All one piece, as far as I was concerned. No air, no space in which to creak, between the two. The battery slide snugly into the back of the phone, and that was that. If you replaced the battery, you also replaced the plastic back door.
My question is: why can't Samsung do that again now? For the past several years, there's been constant braying about the "cheapness" of Samsung phones. It's been a festival of goalpost-moving: first the problem was the plastic, then it was that it wasn't polycarbonate plastic, then it was that the door wasn't "sturdily made" enough.
As an SCH-N330 owner who never found plastic inherently "cheap" feeling, and an iPhone 4 owner who found that under the right circumstances even a phone surrounded in metal and glass could feel cheap if there was a bend in the wrong place (like the iPhone 4's screwed-on, very thin back door), I submit that thinness, in and of itself, is the real problem here. And what better way to solve that than to take a page out of Samsung's own book from the dumbphone era? Just fuse the battery to the back door. Sure, it'll mean the battery upgrades are a tad (and I do mean a tad pricier, but if the end game is potentially silencing a massive host of superficial critics, what's there to lose?