Would it have made anyone any happier if they just jacked up the price of the game, essentially forcing you to pay for the DLC on the disk whether you wanted the content or not? People are not getting short changed here.
They wanted a complete copy of Bioshock 2, and that is exactly what they got. It is as complete a game as any other. You can take or leave the DLCs because they are not core elements of gameplay. Sure, the DLC is already on the disk in the first place, but so what? What difference does that make? It just means it is more convenient because it does not have to be downloaded like a typical DLC (making the "D" somewhat redundant).
The whole thing is a little unconventional, but no one was cheated here. It is like buying a TV and then complaining that you have to pay extra for the porn channels, even though your tv is already capable of picking up the channel signals. It doesn't matter if it is physically within your grasp - you aren't getting it for free because it wasn't stipulated you'd get free porn when you bought the tv. Being able to pick up the signals just makes the whole thing more practical in the event that you do pay for the porn - that way they don't have to go to the trouble of building a load of peripherary shit to change your tv.
For all the complaining people are doing, it is rather ironic: by storing the DLC on the disk in the first place, the developers probably saved a bundle making the DLC, enabling them to pass the savings on to you...so quit complaining! You might have to pay more to download it the traditional way.