I really don't get it. How is it not obvious to everyone that if consumers actually get really pissed off about on-disc DLC, that same DLC will just not be on the disc and they'll have to download it, which is worse for everyone but which apparently isn't nearly as scummy on the part of the publisher?
Remember that game development is not a serial process. If designing characters takes less time than making the rest of the game, and everything starts at the same time, your character designers are going to finish first. You could keep paying them and have them make more characters, but you're only going to do that if there's net expected value from it.
Now, it's obviously the case that some DLC is content that would have been in the game for free if there was no DLC. The marginal value of DLC to a publisher is huge, and it can make sense to trade some sales of your game for more DLC purchases, if the ratio is right. If DLC wasn't an option, you might have included that content anyway in order to generate more sales, but you wouldn't have been able to sell the game at a higher price point because the market resists that. It's perfectly reasonable to be annoyed that DLC encourages this; consumers are right to be sad that suppliers have gotten better at price discrimination. But the on-disc vs downloaded distinction is bizarre and ridiculous. Even the made-before-release and made-after-release distinction is strange; if that were really a big deal to consumers you'd just see some content that would otherwise have been made before release being delayed in production, and due to timing issues this might result in whole games being delayed more often and for longer than they currently are.
So, be upset that we have DLC at all, or don't be. But I haven't heard a not-crazy argument for anything else being particularly bad for the consumer.