Poor user experience.
The market isn't interested in poor screen visibility, fast battery draining and routine overheating and screen dimming issues. It wants a overall trouble free mobile experience. No regular customer goes into the mobile store and asks the rep for the pixel count of the Samsung S5 or passes up a device because it has thick bezels. They're interested in looks, comfort and performance. You tell the average customer that a device heats up a lot or its battery drains fast and that customer is moving on to the next device. The average customer wants convenience from a device. She doesn't want to have to delay her video viewing while her expensive mobile device cools down. To her that's a defect. And she'll most likely return it for a different brand.
And therein lies LG's problem with the G3. It's selling at a good clip at this point. But will the mass market, once it begins to encounter the myriad performance issues hindering the G3, return the device? Or not pick it up if warned about potential problems? I think so. My wife bought the G3 at launch. She encountered some of the issues, especially the battery drain, over heating and dull, dimming screen. I offered some workarounds that did help the device perform a bit better but her feeling was that I shouldn't have to make all those adjustments and compromises in order to make a brand new device operate decently. She exchanged it for a G2. She's thrilled with it. She couldn't understand if the G3 is supposed to be the successor to the G2,why does it have so many problems.
My wife is the mass market. She doesn't know a pixel from a bezel. A benchmark from an MaH. Nor does she care.
But she certainly does care about the user experience. To that end, she's going to spend her hard earned money on a device that enhances her life. She's the mass market.
Inexplicably, LG crafted a gorgeous device, then crippled it with screen tech that the device's engine is not able to keep up with. And to what end? To one up Samsung, htc and Apple? User experience be damned?
Then incredibly, after testing the device, fully knowing the issues the device has, released it to the market as is.
The mass market does not chase specs. It has other priorities.
LG got it wrong this time out.