Why? There is no exploit; to the device, this behaves as any other Android app, subject to its restrictions.
This is indeed very useful, as not all phones may 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.
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.
It is disconcerting because it is a reminder of the war on general purpose computing and devices where the user of the device does not have control of what software is running on the device.
Are you saying that the "rooted/non-rooted" distinction should never have appeared, and that all devices should be "rooted" (for a lack of better word) by default, giving control to the owner/user? If that's what you're saying, I would certainly agree.
This is indeed very useful, as not all phones may 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.
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.