Their website makes it pretty clear that the device is for writing, editing, note taking, and sketching. And it is meant for focus and workflow. Backlight is great for reading, but backlight increases latency and eye strain.

I find it works great in natural light and I agree a backlight would fix the problems with low contrast … but the weeks-long battery life is nice too. Personally I find the long battery life more useful than a backlight. You can always use a reading light same as you would with printed materials.