And this isn't like adding the Weapons to Final Fantasy VII. Because that was the original American release and every subsequent release thereafter. That leads one to assume that they were supposed to have been in the Japanese release but they didn't have the time to get them in before its release. (I may be wrong about that assumption, but still the lines before it remain true.) Therefore, the Weapons are supposed to be a part of that game.
They were added into Final Fantasy VII: International though (which of course was a Japanese-only release, go figure).

The extra dungeon in Final Fantasy II, however, has been added after twenty years of that game being one way. It makes me feel a little weird that this game is being changed that way this long after the release. It's a publicity stunt, I believe. People think, "There's a new dungeon. I have Final Fantasy Origins, but it doesn't have a new dungeon. I'll buy this too." Every time they rerelease a game (or system), they have to do something to it to make people who already have it want it again. How many times did they release the GameBoy? The GameBoy Advance and the GameBoy SP were exactly the same thing, yet I know people who bought both. Don't tell me the minor changes as I know of them. The point is, the SP didn't play any new games, yet people who owned the Advance bought it. I made a comment about the stupidity of Americans in a previous thread. This is what they do. They take advantage of American stupidity. And more power to them. This keeps stupid people from having enough money to do anything really stupid. They make a minor change and suddenly everybody wants it regardless of whether they have it.
Dawn of Souls had an additional, short, and very difficult campaign after completing the game.

And of course ports and remakes should receive bonus content; it's what justifies porting the same game with a cosmetic upgrade. Some people don't care about these additions and don't buy the game, some people want to experience them and buy the game. I don't see where "American stupidity" comes into this.

And personally I found the SP/DS's better built-in lighting to be well worth the purchase price.