[seec]

Yes that's mostly the reason. But considering there are report of display issues like we used to on poorly cooled Intel iMac (those things would get to 90 degree at the PSU, being over 50 degrees on the aluminum case outside) I would say this design is largely a failure.

They should just have separated everything in the foot, that would have made sense. Some sort of modern Sunflower iMac if you will. But Apple is more obsessed with thinness than practical design, so we get an impossibly thin iMac will all the flaws that brings...