Because the OUYA lacks a hardware recovery button combination.
To create a safe environment where the end user can flash their OUYA with confidence.
How This is Achieved
By switching the roles of the boot image and the recovery image, the user is presented with a customized recovery before entering the actual ROM. This gives the user a failsafe before they start to flash their OUYA. This way if something were to go wrong in the flashing process, the recovery image is still in tact and the system can be restored to a working state.
Custom font size that looks better on HDTV's.
Custom color scheme that matches that of the OUYA theming.
Custom reboot options.