Why does chromecast require an Internet enabled network connection...? Can it work with out internet ?

[MikaSch]

What did you think Chrome-cast was ? Didn't you check all its features and requirements before you bought it ?

Chrome-cast is internet enabled device that lets you watch TV without really having any kind of cable Television subscription. It works with internet only. The device connects to the Internet through a Wi-Fi connection to the user's home network.
Chromecast works in two ways, both of which stream content to a television. The first employs mobile apps and Web apps. The second, called "tab casting", can mirror almost any content displayed by the web browser Google Chrome running on a personal computer.
So the above information clearly talks about the requirement of a network for 'Chrome-cast' to work.

Read up more about 'chrome-cast' in the link below.

http://en.wikipedia.org/wiki/Chromecast