Makes sense. Single-purposes devices are kind of cool. It's why eBook readers have a place in a world where tablets exist.
I don't know about AlphaSmart though - the screen is too cramped. I suspect after the initial euphoria of finding another way to write wears off, the author will get tired of the limitations and go back to writing on a tablet or PC. Having said that, maybe there is a market for a writing-only device, similar to a read-only eBook reader.
The screen is not really relevant in this case since the point is to get words onto the page. It is to avoid procrastinating enabling distractions in this author's case, but I have also heard of authors turning off their monitor while writing to avoid premature editing. Other authors find archaic software most effective, while some use modern applications that are designed to display as much or as little information as they need.
It seems as though writing is a highly individualized process.
I don't know about AlphaSmart though - the screen is too cramped. I suspect after the initial euphoria of finding another way to write wears off, the author will get tired of the limitations and go back to writing on a tablet or PC. Having said that, maybe there is a market for a writing-only device, similar to a read-only eBook reader.