"Most people aren't carrying a desktop computer around, so it doesn't matter if it's light."
My iMac is one heavy machine. We've nicknamed behemoth for a reason. I don't have to move it that often, but those memories of when I do are strong. Especially since we don't have a car and had to walk and/or use the bus with it a few times over the last two years.
I often travel with my iMac, precisely because it is so thin. I can fit it into my suitcase along with lots of clothes and bring it on trips with me. Sure, a laptop would work as well, but it's not nearly the same thing.
Over time as Moore's law does its thing, we'll probably see a convergence of form factors and an iMac will simply be a larger MacBook/MBA/iPad.
My iMac is one heavy machine. We've nicknamed behemoth for a reason. I don't have to move it that often, but those memories of when I do are strong. Especially since we don't have a car and had to walk and/or use the bus with it a few times over the last two years.