An important part of our desktop activities is the quick ability to shutdown, restart, suspend the computer for various reasons (switching from one installed OS to another, applying restart for specific application's install requirements, etc).
Ubuntu 12.04 LTS removed the power commands (shutdown, restart) from the Dash (removed the .desktop files), meaning, the developers have removed the ability to easily shutdown, restart, etc the machine via the Dash, "forcing" the users to use the Unity panel/top bar, where the mentioned commands are 1-click away.
