iOS 7 needs buttons for navigation. It offloads some of the increased white space. The users also like them and are used to them. Buttons can also be more easily increased or decreased in size than text links. Text in a button can be shortened if the center title is long. Example: (Voice sett..) A button also is intuitive to press than a text link with no underline. The user know when they have pressed a button because it changes color or some other animation. The text links in iOS 7 let's the user hang in a vacuum until the next page comes in view. The same example with text links would be: Voice sett..Main settings. The designers and engineers will have a nightmare on their hands if they go with navigational text links. They will have to check every old and new page in iOS against so many languages.