The YouTube built-in app found in iOS devices ever since the iPhone was released back in 2007 will no longer be available in iOS 6 or newer iOS updates. Apple today removed the YouTube app from iOS 6 beta 4. Apple removed the YouTube app from iOS because their ‘license to include the YouTube app in iOS has ended’, Apple told TheVerge. Apple also confirmed to the Verge that Google will release its own YouTube app in the App Store.
Our license to include the YouTube app in iOS has ended, customers can use YouTube in the Safari browser and Google is working on a new YouTube app to be on the App Store.
This is not a bad thing, the YouTube built-in app by Apple has always been inferior than browsing the YouTube mobile version on Safari. It offers more options like replaying to comments, enabling/disabling high quality, and opening links from videos description.