Yes, when it comes to companions it mostly seems to work that way, although sometimes you can take the 'bad' path and 'appeaze' your companions - provided your Warden passes a few checks ;)

I can understand getting it because you REALLY want to play the game as soon as it is out, but to support the dev team? If a team wants my support (ie money) then they better not sell only part of the game at full price and then ask me to pay for extra to complete it. There is no excuse going into places (in game) only to have some character tell you that you need to buy a DLC to play this part of the game which was removed from the full game.
I am just saying...
They did something like this (DLC) with expansion packs, but at least there you were getting a meaty product. Look at C&C Zero Hour etc.

Never worked in a software development project have you? Content is completely locked 1/3 of the way into a project and cannot be changed without jeopardising the completion of the project.
DLC like this would be stuff that they might have thought of but was removed because it simply wasn't good or ready enough even if the content was half finished, they have to be ruthless. For an example of a project that lacked that level of ruthlessness, see duke nukem forever.
When the content is already half finished or at least designed, its not hard to complete it after the game has gone gold.
The argument that content is chopped from the game exclusively for the sake of selling later is only really valid for those dodgy situations where the content is already on the disc and you just buy an unlock code

I've heard this before, and I can almost buy it, except then there are the cases where hooks for the DLC are included in the shipped game (e.g. the guy for Warden's Peak in DAO and the door to the Orrery in Oblivion). Do those things just not count as "content" in the model you described? Are they locked in early with the full intention of releasing DLC for them? Thrown in haphazardly at the last minute despite the rest of the project being locked in? I'm actually curious to know about this.

Don't you just yern for the days when they gave it to us for free?
Trials of the Luremaster comes to mind.

Or Rise of the Triad full episode Shareware.

If you actually play some games like DAO as DarrkPhoenix says in the post after yours, you will clearly see the bullshit behind argunments like that by them (not yourself). As with all the DLCs which are available from the day one of release. And since we are not talking about days when there was no digital distribution...yes, I call BS on any such claims by them.
I might have never worked in a software development company (projects yes), but I have bought many games and I value my money to decide what to do with them for any reason I want to. So yes, what I said, stands.

Thank you for giving more detail on my example. I was perhaps expecting too much for anyone who hasn't played DAO to know what I was talking about.

So, since they ruined any male pcs that romanced Morrigan by giving you a stupid resolution with the romance subplot. So, yeah, I'll be getting this just to continue my pcs futile attempt at being back with her.
Oh yeah, Duncan told you that Wardens can use blood magic despite the fact it is the evilest form of magic or something. So, yeah, totally gray area since you have to use anything to stop blights.

Okay lets look at the situation. They've been developing DAO for something like 4 years and the final game content (the plan that is not the implementation) is locked after say 2 years. When they're designing the game, they come up with a lot of story they want to tell but haven't got time to make, can't polish to an adequate level or would simply delay the core content in favour of something peripheral.
They realise that they have a lot of interesting side quest ideas that can't go into the core game and they're too disconnected to make into an expansion but then they get the idea of selving them until the core content is complete then taking the people who were doing the core content and shift them over to doing the DLC.
When they realise the DLC is clearly going to work, it really takes a negligible amount of work to add a single, generic NPC who's completely disconnected from the real world and as such has absolutely no consequence to the story and can't be affected by any ingame events and give him a single conversation tree which amounts to "If you have the DLC would you like to play it? yes/no". That sort of character cannot affect or be affected by the world or characters around him and acts as a play button, in short he is 100% isolated from the rest of DAO and as such could be made in literally a day's worth of work.
Also, I'm pretty damned sure that he wasn't there to begin with since the content wasn't launch ready, at least I sure as hell never saw him and when I first get a game I do tend to explore absolutely every millimetre so I'm damned sure I'd have noticed.
Was it a bit of a dick move putting a walking advert into your camp? Yes
Was it evidence of the content being ready for inclusion in the game and then being cut out by an evil mustachioed executive whilsy laughing maniacally thinking of all the hard won pennies he'll steal from sad orphans? No
Now I only have the GOTY Oblivion which came with everything already so I'm not sure if its the same deal there but I'd not be surprised if there was a single otherwise irrelevant character spruiking for the characters attention.

As much as the endless whining about DLC annoys me, the hooks are terrible. I never knew the guy in Dragon Age advertised in the game because I bought the DLC day one, but when I found out it disgusted me. That should NEVER happen... the game on release day should be complete.
It's the only thing I dislike about DLC, which otherwise I consider to be often good and often bad, same as any release of anything.

Wasn't because I played good that I disliked her but because she was in my books the stereotypical 'Chaotic Stupid' character. Plus, if they are going to introduce such a character then they should either provide a greater reason to not kill her than plot armour or simply not put her in a position where you can kill her. If you choose to reject her offer you get to say "I should have killed you!" to which my response is always "Why can't I kill her?" I should have been able to poke her with my sword (and not the pork sword she wants) and the fact that not only can you not but they even rub your face in it repeatedly is what gets on my nerves.
That's why I don't like her character, she is just too contrived to be bearable.

Knowing companies it could just be the DLC files on a disc that still need activating, who knows. I hope it is a completely DRM-free compilation though, and I would buy that despite buying the DLCs individually when it reached <$20.

You couldn't kill her because her destiny was still unfulfilled (and by "destiny" I mean "DLC milking"). Also bear in mind that I don't think they have allowed you to directly and deliberately off a companion (or ask someone to off them for you) since Knights of the Old Republic. Both Mass Effect games have companions that can die, but only by proxy as a side-effect of the player's actions or inaction (with the partial exception of a potential "either A dies or B dies" dilemma in both games), and characters who are potentially dangerous or even demonstrably Chaotic Evil are merrily brought into the fold "for the greater good" without a second thought.
A crucial reason for such an option going away is that they have moved away from morally flexible protagonists with uncertain futures to protagonists that are fated to be the good guy in the long run and can only do slightly questionable actions along the way for the greater good, sort of like a pussified Jack Bauer. Killing a companion falls a bit too far off the side of evil for Pussy Bauer, especially since the companion's questionable morals were typically known when they joined but brushed over with a "use the tools of evil to fight evil" speech.
Unfortunately, BioWare's "ends justify the means" options generally backfire because very few allow you to make significantly debatable decisions (like letting some innocent people die in order to potentially save more lives in the long term); most of them involve small-scale acts like fleecing a widow out of her dead husband's possessions or demanding more money for a job, things which simply aren't going to help the war on terror (replace with Darkspawn or Reapers as appropriate) in any tangible way and just make Pussy Bauer look like a total jerk.
Having companions able to be killed off also complicates matters when it comes to DLC and series continuity. Mass Effect 2 allowed saves to be imported, which was a nice touch, but if a person had been killed on your save they are replaced by a conveniently equivalent character, minimising the long-term significance of that character's death (in terms of both plot development and gameplay functionality).

Dragon Age Origins is already DRM free unless you seriously count a Disc check as that inconvenient. The DLC has probably the lightest DRM in the history of DRM.