Why android is power hungry? When every android phone is released, all the reviews discuss about battery life of the device, since, they say, battery life in android phones is a critical issue. 

Question is :

Why battery life is an important problem in android phones ? 

Some say, it is due to the display of smartphones. Some say, Android is inherently power hungry due to some of its OS related features.

Can anyone highlight the reason why Android is power hungry ?
Just a few reasons Android uses a lot of power:


Large, Colorful, Bright Display
Constant Wireless Connections
Background Applications
Application/Cloud Syncing
User Input
Garbageware Applications running when no one asked them to
Poorly written applications using more CPU cycles than needed


Basically, everything about your phone that makes it "smart", uses battery power - often a lot.

If you were to dim the display to minimum, turn off all wireless communications and have no applications running and syncing, your smartphone would have outstanding battery life; and be quite useless.