Actually i have to weigh in on this, and im actually ignoring the other Zeel Thread because..well thats a flamewar waiting to happen. Im actually counting the Minutes it will take, but lets move to the point here.
DLC has no bearing on being entitled to anything. However what DLC should be is Additions to the Game, more Quests, more Content, stuff that is not entirely related to the Storyline of the Game. I shall take recent Bioware Games as example, not just ME3.
Long ago, before the Internet was as big as it is today, before Piracy was as widespread, there existed Developers, and Publishers. And they both had one big Goal and one Job they had to do. The Developer creates a Game, a world, narrative, ending, characters, everything. They polish it to such a degree that its going to stay on the minds of the consumers for as long as possible, so that they will fondly remember all those Hours of time spent in these fictional Worlds, replay them at their leisure even. Publishers of course kept check of the bottom-line, they have to market the product, sell it, move the PR along, make People aware it exists and why they should buy it.
Now that we have that out of the Way, lets look at how we are today. The Publisher dictates how long Games can stay in development, they can even entirely abandon Games if they wish, they have far more power than they need and far too much influence on the creative process at work. Of course you cant take forever to polish that nifty Game you're making, but it should be released in its best State possible, not just "when its about ready". If i order a Steak medium-done, i expect to get a Steak medium-done, not well-done and have to complain to the Owner of the Establishment to get my medium Steak, or pay some more Money to get it. But thats a analogy and probably isnt sufficient to get the Point across here.
Mass Effect had DLC, the Game was done, finished, it was all there, the DLC you got? It wasnt mandatory to have, you could buy it, extend the Time spent on the Game. They werent essential to the Plot of the Game or anything similar. Dragon Age Origins had DLC as well, even a full-blown Expansion. Again the whole Game was there, nothing was missing from beginning to end, it was all pretty much self-contained and all but one DLC just explored Questions left after the Maingame ended, or even offered a Way to continue afterwards with the Expansion as the big example. Only one DLC was tied directly to the Plot, but was not essential, it wasnt required, you werent left hanging with countless Questions for not having it. Now lets move a couple years into the future.
ME2 had DLC, a load of them, far more than its predecessor did. Some were good, others great, but also a couple lackluster ones. Zaeed for example, you wouldnt exactly miss him in the overall Plot of the Game, he doesnt exactly bring much to the Story. Same goes for Kasumi, of course both have impact on the Sequel but thats a different Point. Project Overlord? Great DLC, it gives us some exploration, some stuff to do outside the Mainstory, it doesnt exactly factor into it as strongly. Lair of the Shadow Broker however does. The moment you meet Liara, its obvious that the DLC is planned, granted maybe at release it wasnt that the DLC was later, so they moved it back, understandable really. So im not going to fault that, but Arrival? The actual proper Ending of the Game is a DLC, a bad one at that, its short and offers relatively little in comparison to its cost and place in the Storyline.
DA2, released in a pretty good State, as much as Fans might hate the Game, well maybe its not Fans anymore, but thats not important, it was done pretty much. The Cliffhanger ending? Well it sucks a bit, but you can see why, its a set-up, the world has gone down the drain, cant explore all that in the same Game. Yet we have DLC as well, one was fairly small at Release, the other not so much, it contained, as with ME2, a Party Member, in fact a fairly important one that actually had impact on the story and made a late-game Decision all the more important. I cant speak for the others as i dont have them but lets just say, according to what i could get from what i've heard of it, its a bit similar to what Lair of the Shadow Broker did, it gives us Answers, explains a few Points, and potentially even explains the Ending better, but i cant say for sure. So anyone that has played it can probably judge it better than i could.
Now ME3 follows that same Logic. Good Game, but the Ending was terrible. So People are hoping it can be fixed with DLC. Thats a Problem, may i point out its Arrival all over again, it doesnt need to exist, not because the Endings were good by any means in ME3, but that we should have to pay to get the complete Game that we should be having already. DLC is added Bonus, Content beyond the mainstory, in-between, before, after, either is fine, but if it has a big Impact on the storyline of the mainstory, it should be in the Game already from the start, and not held hostage behind a pricetag.
Does that line of thinking mean someone is entitled? Yup. But when you pay 60 Bucks for a Game, then you are entitled to get the full Game, as is, DLC and Expansions are OPTIONAL, and lately thats changing where Developers and Publishers alike are moving to a point where Content is withheld from us that should be there already, they are making it mandatory and ask for even more Money up-front for Stuff that should already be there. Of course it would be entirely different if they came out and said it directly, that some Content will only be available after paying a small extra cost, you cant complain then, but it should be obvious on the Box of the game, not be a afterthought of the publisher or developer.
If the Game costs 60 Bucks, is advertised basicly as a full Game, with all its content in place, then im entitled to all that Content. Its really that simple. Though Bioware is better at hiding the missing Pieces a little, they arent glaringly obvious, like for example Fable 3 was in comparison, but the Point is still the same.