Why? There is no exploit; to the device, this behaves as any other Android app, subject to its restrictions.<p>This is indeed very useful, as not all phones <i>may</i> be rooted (an issue of legal permission between owner and user, not of technical possibility), and this app enables a pseudo-root, sandboxed system that can be seamlessly uninstalled like any other Android app.<p>Also, the attack surface of a rooted phone is siginificantly larger (by necessity) than that of an unrooted one; plus you may want to give your users a portable desktop computer without necessarily giving them a rooted device.