over in the "Motorola Moto G (GSM, 2nd gen.)" discussion:
Difference between 1st and 2nd Generation Moto G
I don't really see any compelling reason to upgrade to a 2nd gen Moto G. CPU is pretty much the same, 3MP more on main camera isn't compelling enough, Storage space is the same and the only thing that I could appreciate more is the ability to use a SD Card.
If Lenovo continues the the Moto X and G line I hope the next version has more features to compel me to upgrade. If not. Then I don't know what to say.
They are making them bigger because people want them to be bigger. If you are going to be doing serious web surfing, shopping, playing games, apps with a phone you want the screen size to be big enough to actually see what you're doing.