StealThisSheen posted... The Tweet in the topic post is dumb, but I'll also never understand this mindset, either.
Take a fighting game, for example. If they advertised 30 characters, and I bought the game because 30 characters was enough for me, cool. The game is complete, since they gave me everything they advertised that they'd give me before I spent my money. If they then add more characters later on as DLC, that doesn't mean the game is now suddenly "incomplete," because I had already decided what I was getting initially was worth the money I paid initially. They don't owe me anything more for free. It'd be nice if they give it, but they certainly don't owe it to me, because I deemed what they offered initially to be enough value.
Advertising a fraction of a game as a full game, doesn't make it so.