This is my theory for why Microsoft added a 24-hour online check requirement for Xbox One. There are a few things you have to understand before we get to the DRM.
It is clear that Microsoft wants to switch to an all digital system. The very fact that discs become coasters so soon after buying them is enough proof of that.
If that's the case, though, why does the Xbox One support discs in the first place? Why not just distribute games like Steam? It's a good question. The reason for this is twofold. First, even though Microsoft is certain that most households in their target countries will be able to provide the minimal internet connection needed for their DRM checks, they are probably afraid of a situation where users can't buy Xbox One games because their internet doesn't allow for the kinds of large bluray-sized files needed for next gen games. Installing off of a disc eliminates this potential problem.
The second reason is retail. Even though Microsoft could foreseeably cut retail out of the software game, Microsoft would have an INCREDIBLY hard time selling the console itself without the aid of brick and mortar stores. Given that retail will still be important to Microsoft, they need to give retail a reason to stock the X1. Not too many stores would want to heavily promote or give much shelf space to a product that sells only itself when there are products like the WiiU and PS4 that will provide more long lasting revenue streams through continued software sales.
So, even though Microsoft wants all digital (like apple and steam), it still needs to support discs.
Used games. Microsoft would probably prefer for there to be no used games. This would help them control their market, it would make publishers happy, and it would help stop piracy. If that's the case, then why doesn't Microsoft eliminate Used Games?