I suspect this is more a function of the fact that the LCD screens are in portable unit and subject to repeated abuse, and that the video connection is passed through a little ribbon cable inside a hinge. Just a hunch. I'd love to see actual failure rates between AIO LED LCDs and laptop LED LCDs.
Oh, I know most of the failure rate on laptops is due to portability. The ribbon cable is actually not a usual failure point. Pressure on the screen shell, or dents to the screen shell, outright shattering.... common accidental damage. No AppleCare.
But LCD screens do fail, technically, and not due to outside influence. backlight failures, colored or dead lines in the screen, or out-right black-screen failures do happen. Sometimes due to video card over-heating or damage... (common PC problem)... or screen component failure which is a bit more common on Mac laptops... the video systems do fail, but not quite as often, it seems, and are kept cooler by shunting the heat through the aluminum skin, as well as cooling fans exhausting into the hinge area.
Again, my dad's iMac's final failure mode was a black screen. All of the signs of startup, but no video signal. Not just a blown back-light.
If it was a main logic board/video system failure, a separate CPU could be replaced. Maybe even a PCI-slot video card replacement without having to replace the whole CPU unit.
If the black screen was due to an LCD failure, a monitor replacement would have been all that was necessary, and the CPU, software system, and data would be ready to go with a new video output device.
instead, the whole iMac had to be chucked, and the hard drive retrieved, and converted into an external, just to reclaim that value and data.
MacMini was suggested, and the form factor was a plus... the fact that it didn't have the performance of the iMac's hardware, new vs. new on the same purchase date, swung the decision to iMac again. If the MacMini had had the specs to compete, it probably would have been chosen, instead.
