I am a FIRM believer that a quality product will net you more sales than any cheap tricks will and if you really come out with a banger then you always have the option to add a MEANINGFUL DLC addition down the line, instead of content you made at the same time you made the base game and just decided to wall off and "release" later.
How many hours do you have in game? Had you played you would know that nothing available is "walled off". It is actually the opposite, and the stuff is basically useless to buy since you can acquire all of it through a normal play through of the game. No place in the game do you even feel like "oh man, I really need to buy that DLC or else this part is going to be impossible/different/less than/etc.".
And it's clear the people getting everyone all riled up about this stuff did not play the game either (or are acting in bad faith).