I'm in two minds about the controversial "issue" that is on-disc downloadable content. I don't necessarily see the concept in the same capacity as some gamers -- some people genuinely seem frustrated at it -- although I am lost as to why something is still referred to as "downloadable" when it is in fact already on the disc.
As for downloadable content in general, it often fails to truly enhance and expand an experience: Rockstar set a standard with its DLC for GTA IV and Red Dead Redemption, although few since have offered extra content the size of a full game for the price of what some publishers are charging for a couple of maps.
That's disappointing as a gamer, and frustrating as a consumer, but the size and worth of DLC is a different issue than the accessibility of said content.

Twisted Metal designer, David Jaffe, recently compared on-disc DLC to a McDonald's meal, in that a BigMac was a game and the burgers cooked on the grill after it were the on-disc DLC.
There's plenty wrong with that metaphor. Firstly, I'm not buying a BigMac and then paying extra to add the meat, something that should already be factored into the price of the burger. Secondly, burgers made on the grill after my BigMac are equivalent to either DLC of the Lost and Damned variety, or a new game all together.
I don't think gamers are frustrated at having to pay for the extra content. It's the fact that the content is already on the disc, a product they've already bought, that causes the issue. Looking at a game like Street Fighter X Tekken, where 12 "exclusive" characters were available for the Vita version but were already on the disc as "DLC" in the console version, and it's clear that, maybe, perhaps, publishers are trying a little too hard to push the need for DLC on developers.

In this instance, Capcom has actually defended its stance.
"While Capcom is sorry that some of its fans are not happy about the chosen method of delivery for the DLC, we believe that this method will provide more flexible and efficient gameplay throughout the game's lifecycle."
Meanwhile, it's removed on-disc DLC from the PC version of the game, which is interesting considering recent comments by Gears of War designer Cliffy B.
Mr Bleszinski said that the best way to get rid of the issue is to offer "fully downloadable games".
Which he's probably right about, and certainly adds worth to Capcom's own justification as to the distribution of DLC.
That said, and I feel I need to reiterate this, but something that's on-disc is not downloadable, and the issue remains in charging customers for a product they've really already brought. Why not just raise the price of the product and include the extra content in the final game?
Maybe as we make the transition to digital distribution the issue will slowly disappear, but at the moment it still presents an interesting moral dilemma for publishers, and a frustrating concern for gamers.
By Gaetano Prestia - Tweet @Gaetano_Prestia
How do you feel about on-disc DLC? Do you think it's an issue that publishers and developers should look to stop?