Because that's exactly what the world needs, another alarm clock! I wake up to my iPhone, so I guess Sony figured PS Vita owners would want the same. But do they really need to get Trophies for that?
Besides a variety of skins, there's "Mezamashi Doumei" or "Alarm Clock League". It's built on the concept of "encouraging others to wake up at the same time", and that's a concept that sounds creepy as hell.
In the video, you can see the PS Vita owners, waking up and tapping Avatars of PS owners that are supposed to get up at the same time. If you don't wake up within five minutes of when you are supposed, you'll be spammed with puffy clouds. Nothing like busywork first thing when you wake up!