Software piracy existed big time before the term "DLC" or even "download" made any sense whatsoever. Or expansions. Or what have you.
And once expansions came along, people queued up for them in the shops. A CD with all kinds of extra content for Civilization II - sign me up, certainly worth the half price of a game.
However, I will argue that DLC is - in general - a good thing. While a full blown game is more expensive than in my youth, the rise does not compare to inflation. And when buying stuff, you can buy the base stuff and see if "more of that" is worth more money to you. Granted, not every game is made for it in the same way, and not every DLC is as useful as others (did somebody mention "horse armor"? Oh yeah, somebody did. Only very shortly ago. By the way, I am a proud owner of it, though admittedly only in a bundle with Knights of the Nine, would never have bought it on its own). And not every game is handling it well (looking at you, Dragon Age: Origins - the DLC was worth its money, but the way the game behaved without installing it by advertising it was annoying).
But in the end, porn games also have to be made by somebody. And they do not necessarily do it just for the enjoyment of others. So stuff like that is going to happen, and why not? I personally hate it for a different reason, namely Steam having stopped allowing buying adult games over here (let's not get into the reasons, in the end I understand both sides here, however, personally I hate it), so I cannot play it without pirating. And yes, that would be the "service issue" mentioned by Steam Guy. However, that ain't an absolution to just go ahead and pirate because it's the other side's fault.