It all boils down to productivity and ergonomics.
I have not found any better place in my house to do something for an extensive amount of time then at my desk (and at my desktop computer). The desk height is ideal, my screen estate is large enough and it's positioned at the ideal height, I have an good chair and can sit up straight without getting pain somewhere after a short amount of time, I have a large keyboard and a good pointing device.
Any other place in my house requires me to adapt to it and there are compromises. Either the chair is not ideal or the screen is smaller or the keyboard is compact. Don't get me wrong, I am able to manage but simply not as comfortably and productively.
If you are constantly on the go, you don't have a choice but "any area" (in the home or office) will not be taking over the desk area (or desktop computer ) any time soon if you need to do some work.