Why do the start ups need to be Arduino-based? There are a lot of excellent microcontrollers on the market aside from the ATmega. Also, that form-factor doesn't

Why do the start ups need to be Arduino-based? There are a lot of excellent microcontrollers on the market aside from the ATmega. Also, that form-factor doesn't seem well suited to most applications. For example, this thing has most of the capabilities to build a Nest (http://nest.com/ http://nest.com/) knock-off. However, it wouldn't make sense to use that board design. Also, the cost would be much lower using a single SoC to do everything. The Yun only includes the ATmega paired with a Linux SoC so you can add WIFI while still using regular Arduino sketches.