I agree.. the interesting thing is the the EU has already ruled.. US lagging. Link to wikipedia below. They say that a first purchaser can legally sell their licensed product (even though it does not "degrade" like most physical products). The one catch is that the orignal owner must no longer be able to use the licensed product. That has been impossible to implement and seems to be exactly what the xbox one does:
http://en.wikipedia.org/wiki/First-sale_doctrine
Application to digital copies
However, in Europe, the
European Court of Justice ruled on July 3, 2012, that it is indeed permissible to resell software licenses even if the digital good has been downloaded directly from the Internet, and that the first-sale doctrine applied whenever software was originally sold to a customer for an unlimited amount of time, as such sale involves a transfer of ownership, thus prohibiting any software maker from preventing the resale of their software by any of their legitimate owners.
[3][4][5] The court requires that the previous owner must no longer be able to use the licensed software after the resale, but finds that the practical difficulties in enforcing this clause should not be an obstacle to authorizing resale, as they are also present for software which can be installed from physical supports, where the first-sale doctrine is in force.
[6][7] The ruling applies to the European Union, but could indirectly find its way to North America; moreover the situation could entice publishers to offer platforms for a secondary market.
[4]