
The reason for the switch to a larger form factor lies in the lower than expected sales of the 2013 Nexus 7 and pressure from smartphones with large displays.
The Nexus 7 has accumulated sales of around 3 million units, way below expectations, according to the sources. The share of compact tablets (with 7 to 8-inch displays) have grown when compared to full-sized 10-inch devices, and competition has increased.
Phablets like the Samsung Galaxy Note 3 have also boomed in popularity, and with the small difference in screen size between them and 7-inch tablets, the reasons for buying a tablet have grown less strong.
source: DigiTimes