The possibility of a console that prohibits one from playing used games would be a massive blow to many frugal gamers, as well as the number one retail chain dedicated to gamers. Because those on a budget make a large contingency of their customer base. One that would not support a console if such restrictions were in place.
VG24/7 reports that GameStop's chief financial officer Rob Lloyd addressed the matter when speaking at the Goldman Sachs Technology and Internet Conference. His presentation was described as essentially being a defense of the used game trade, something that many publishers are not fond of:
"It’s really only about 4% of our used game sales that are games released in the last 60 days… Sony has said publicly that they don’t intend to block used games on its next console. Microsoft has refused to or has not commented on the rumours."
There have been many reports already that state that any new system that blocks used game sales would cause a massive blow to the bottom line of the company that dares to produce one. Which is why the aforementioned reports that the Xbox 720, or whatever the heck it will be called, is so perplexing to many.
Lloyd went to state that his company polled their customers about the matter:
"Consumers want the ability to play pre-owned games, they want portability in their games; they want to play physical games. And to not have those things would be a substantial reason for them not to purchase a new console… I think it was 60% of customers who said they wouldn’t buy a new console [if it blocks used games]."
As VG24/7 also notes, GameStops stock took a hit once rumors that the Next Xbox might block games. The company as a whole has been struggling, largely due to the rise of digital downloads. 250 stores are set to be closed this year, though 60 to 70 will locations that presumably are completely brand new to the retailer.