Phablets... Born out of Necessity.
I marvelled recently at how easy it was to type on a friends new Samsung Note 5... that it was the first touch screen I had ever used which I found as easy to actually write a long correspondence on as my old Q10. Then it suddenly dawned on me... the problem all along was that with my big fingers without the tactile feedback and 'alignment assistance' of a physical keyboard devices simply had to become larger.
A friend and I challenged a few other friends to a type off with four devices... an iPhone 4, an Samsung S4, my Q10, and his Note 5. Across the board everyone agree that the iPhone 4 was the worst device to try to actually type anything on, most people preferred the Q10 to S4, while most preferred the Note 5 to the Q10 for typing. However, one thing which everyone agreed on was that the device they were most impressed by was the Q10 for the simple fact that it is by far the smallest device which they could comfortable compose a longer email on.
20 years ago it was all about miniaturization - the past few years it has been about who can make the largest phone driven by how much more usable larger touch-screens are. I know our experiment wasn't very scientific, but it BlackBerry came out with a Q10 sized device running android I suspect there would be many who would consider the device. Problem is that, unless you have small fingers, for a touch-screen keyboard to be easy to use the device ends up being larger than comfortably fits into a shirt pocket.