DLC
Expansion
DLC = Expansion.
Seems to be the same to me.

Maybe the OP is crying over nothing?

DLC and expansions are not the same thing. DLC is designed to extend the life of the game (and, according to developers, keeping the team paid) by spreading out smaller additions over a certain periode. DLC is distributed exclusively through the internet.
Expansions, back in the old days, were just what the word said. Expansions on the game. More often then not it became a whole (albeit smaller) game in itself where the setting was different from the main game. Think Throne of Bhaal or Shivering Ilses. Good (and populair) expansions did more then add a few bits of armour, a quest or a NPC. It built something entirely new.
For publishers, the DLC is vastly more profitable, you don't need to be Adam Smith to figure that out. A relatively cheap distribution system is one of its charms. The other, of course, is keeping the core team paid (and not having to move them on to other projects). But I suppose the real boon for publishers is that DLC is designed to add little things which were conceived earlier but cut - either because of deadline or the prospect of using it as DLC.
I, for one, vastly prefer expansions. I always pay for games I play, and expansions on good games are welcomed by me. I rarely see it worth it to purchase DLC. I've been following what Bioware/EAware has been doing and I'm not impressed. Who really cares about a crappy extra piece of armour, weapon or shallow NPC? I'd rather pay for more creative effort then that.
Unfortunately expansions as a business model appear dead and considering that a lot of gamers are hungrily buying substanderd DLC, I fear that is the way of the future.