This mentality baffles me. I have bought several houses second-hand... does that mean I stole them? (...)
The industry is pushing hard to outlaw a right that always existed. People have been trading books for centuries (and the anology between a book and a piece of software is fitting because, in both cases, you own the support, not the content)
However, it's true that the publisher doesn't earn anything from a second hand sale. This is the first reason why the media industry as a whole is looking with interest at digital distribution method. The second reason is that, in case of digital distribution, unsold copies doesn't occupy shelf space prompting store owners to deflate the prices of perfectly valid products for no other reason than clearing the inventory.
I can go out and buy a new, boxed copy of Skyrim for PC at 29.99 or buy it via Steam, still at 49.99. Looking at Steam sales charts, however, I'm beginning to think too many people are either plain lazy or have too much disposable income.
Console owners still have the 'luxury' of being able to buy used copies, at least until this generation lasts. I look at the Steam 'Top Sellers' chart weekly and Skyrim has always been there since its release. Most of the time it stays in the top 20, which is actually amazing for a 1+ year old game. Meanwhile, for the past 6 months, I've seen nothing but used copies on sale at my local Gamestop for the Xbox and PS3.