But it's not about the technology. It's the setting. Wordsworth said you get poetry as "the spontaneous overflow of powerful emotions recollected in tranquility: it takes its origin from emotion recollected in tranquility." (http://en.wikipedia.org/wiki/William_Wordsworth) Now, I don't write poetry. But the basic process works the same way, even for my plain old humble science fiction and fantasy. Inspiration comes wherever and whenever it will, but when I sit down to work it into something worth reading, I need a place as close to a sensory deprivation tank as I can get. A desktop ties me to the same monotonous desk in the same monotonous room, so the environment fades into the background and I can work. There's no temptation to take the gear on the road and write in the park or by the river or wherever.
I think it would take more discipline than I have to work on an iPad and not be tempted to think I could get things done anywhere. I'd have to nail it to my desk. But if I did, I'd give you the point. It's not the technology's fault.
Wood already works for "carbon fixation" and you can make things with it that people will actually keep. My mother has some "fixated carbon" in the living room over 100 years old. Just grow a tree and make a desk.
Why use a simple, cheap solution when you can pay so much more for a complicated and less-effective one? The eco-industrial complex can't charge you as much for just growing a tree.