Don't get me wrong I fully agree that some of the policies were harsh and some of the thoughts aren't exactly 100% accurate but Skyblade asked where people were coming from so I summed up what the general to and fro of it was based on what I've read from both sides of the fench.

But to touch on one point as I'm at work and don't have much time:

As far as physical copies? If you want to play from the disc you can anytime on any machine. Want to install it on your hard drive? That requires an internet connection and works the same way as digital copies except maybe you only get the one license to install it, and once you trade it in, all that needs to happen is a store scans it and it's de-authorized so next time you're online you lose the installed copy.
Which would require a substantial hardware installation at retail locations and there's no guarantee the store will even use it. Plus it further reduces revenue of fledgling independent retailers who can't afford such POS systems. The other ultimate irony is it would need an internet connection to update/revoke licenses. "Oh sorry our connection is down, you can't trade games in today."

Likewise what's to stop someone from just claiming that a store forgot to revoke a license or that a friend sold it to you and the myriad of claim of ownership issues it presents. Or heck if you're deployed somewhere and decide to give your copy to someone in a different unit who wants to use their own account. It reduces the options available to consumers which is why people were so up in arms over the DRM concept in the first place.

Believe me as someone who actively works with license bound material and ownership disputes on a daily basis these things aren't as cut and dry as they seem. If everyone played fair a lot of these things would be a non-issue but publishers aren't the only evil here - not all consumers are innocent in this equation either and sadly a lot of these systems have come in as a result of the more *quote fingers* malicious *quote fingers* side of the consumer base.

Now, apparently, some people were all for the idea of sharing plans so perhaps that is an avenue that can be explored with authenticating machines like how iTunes works (similar to your example). Though I suspect the pressure here is coming more from the IP owners and publishers than the hardware manufacturers themselves and they're probably concerned with "what if this person never connects the de-authenticated machine to the internet again." A relatively minor issue to most of us I'm sure but a potential loss of revenue in the eyes of the bean counters.