The Oculus launcher includes the VR runtime that handles all the back-end compositor, tracking, etc -- so that's a necessary part of the VR system (it's does the equivalent of Valve's SteamVR for the Vive/Index).
Not sure about the issue of needing an internet connection for the Oculus runtime/launcher to operate -- I just yanked my ethernet and was able to launch applications from the Oculus library just fine. Perhaps there's some circumstance where a driver or service certificate times out after weeks or months and requires an online update from the store? If he's interacting with content from the Steam store but blocking the Oculus app from updating, then there could be circumstances where the Rift and/or runtime might be out of date and not compatible with up-to-date applications.
i prefer the way steam did it. The steam vr are a separate entity that can run without steam running. But if you did that, it will run DRM free, and will break games that use Steam's DRM.