It really seems like they just want to kill used game sales, which will kill the game specific retailers, which will leave them beholden to the big-box stores (i.e. Best Buy and the dreaded Walmart) to retail their games.
And here's where you're wrong. You are making the assumption that that they will be beholden to anyone. Obviously they don't want that and obviously they know that killing off the small retailers is effectively giving up power to the big boxes simply by reducing competition. So what are they up to?
The upcoming generation will perform various tricks to push downloadable games so that in 5-10 years they will be able to push out a medialess platform without an uproar in the demographics that matter. What kind of tricks? How about a $15 credit to the online store to relinquish the license you have on a current game? How about pushing episodic content, where only the first episode is available in disk format? How about requiring a credit card for "age verification purposes" on Mature rated games (getting the CC info greatly increases future sales simply by reducing the hassle factor of the first purchase)?
You know all those games that you've picked up on sale or clearance or used for $20 after they've been out a year? Those are going to be a thing of the past.