Why do none of these have larger displays? I imagine it's annoying to type without the ability to at least skim over the last page of content? Are larger monochrome displays just harder to procure?
This is already relatively large for this type of display. There is no market for these types of screens at a larger size. (They are mostly used in products that are not connected to a computer such as a controller panel for a factory, or mechanical device.)
I think they aimed for a very portable format. I think it's a bit took much especially considering that you will be already carrying a keyboard anyway.