When people say they own the game, they mean it in the same sense as they own a movie or music physical media, obviously they do not think they own the copyright on the music/film/game... but as long as they have the media they expect to be able to put it in a machine that can read that kind of media and play it, for an unlimited amount of time, without some arbitrary limitations like "you cannot lend the disk to more than 1 friend, you cannot sell the disk, you cannot watch it more than 5 times, or you cannot play the game after 1 month, etc.".
These are reasonable expectations to have when you buy a disc, imagine buying a game from someone off of ebay and finding out that the license expired when it's delivered to your door because it was re-sold too many times or you put it in the disc drive before you had been friend for more than X number of days? or you tried to re-sell it through an un-authorised delaer... or the original owner forgot to un-tie the disc from their account.... these are limitations that can be added to physical media if you tie them to an on-line account.
Still, I would like to be able to "tie" physical games to my PS4 temporarily and play them without swaping the discs, then when I want to sell one I can just un-tie the license from my machine (either on the console on from the PSN web site) if the DRM server is down, then the console asks for the physical disc to be present (this way if you go on vacation and want to bring your console, you have to bring the discs for your physical games, but at least you can do it).... obvioulsly if MS offered a system similar to what I describe there, there would have been no problem, it gives you flexibility and control of your media as well as giving you the benefits of the digital games for all titles, if you opt-in!
The problem is not impossible to solve, and a solution that pleases everyone would bave been possible too, neither console manufacturer has done it yet 
