I first want to point out that, since we are all on the internet, very few of us, myself included, actually know what goes on in the development of a game, or the logistics involved in the business of selling said games. With the exception of the writer of this article, I am now typing under the assumption that nobody really knows what goes on inside the industry, so if anybody who reads this actually does know, either by being in a company that makes or sells games, and you are offended by what I'm about to say, I apologize.
The D1DLC thing might 100% be down to faulty programming on the initial product. Shale for example, might not have been able to work properly in the game proper, so they took the time to fix it, then release it on D1. As someone above has stated, Bioware stopped working on the game to give the testers time to find bugs and such. However, like in EVERY game in existance, some bugs either never get found until release, or can't be fixed until later. So, they work on the code to get the game (or in this case, a character) to work, and if they manage to get it fixed, find an alternative way of distributing it to the public. The Assasins Creed DLC is completely different, (I'm hoping, haven't DL'd it yet) as it is not integral to the plot. The game is 100% complete as it is, without the little extras. While yes, it was planned from the beginning (2 memories "corrupted", way to be subtle Ubi), it's not quite as harshly looked upon as the DA:O DLC.
I was going to bring up the used game thing as well, but someone above said it best with his car analogy. For me, without used games there are some series' that I would never have gotten into. I love Silent Hill because I found a used copy of the second game. Used games are a great way of introducing someone to a series they might not have had time to play / money to pay for at the time. I've bought every Silent Hill game new since then, so Konami has made their money back in spades for that purchase. What happens when certain games get discontinued? (AKA almost everything that Atlus puts out stops being in production soon after it's release), used game retailers actually allow you to find said games when normally they'd be out of your hands.
Also, lets take Assasins Creed for example. Once you beat it (and evidently it's subsequent DLC), that's it. Game over, nothing to see here. Places like EB and Gamestop allow people to get rid of their games while paying for others. I'm in Canada, so I don't really know any of the values in the States, but up here the values of the games tend to be pretty fair for what they give. I got 40 bucks for Creed 2, that's more than half of what it cost me... before taxes anyways.
Point is, there is always two sides to the coin. Sorry for the long post, just had to get it out there, and ... well, I like seeing my words