They aren't doing that - you're jumping to conclusions without watching the linked footage or reading any of the recent interviews, it would seem.
I've been following Civ V closely enough, although I will admit after the annoucement of a Steam exclusive I stopped chasing down every piece of information available. From what we have available, they're stream-lining the experience to make the game more accessible. Part of this is masking information that the player has to make the systems less 'thinking' intensive.
Frankly, some of this sounds well and good. Civilization IV was, and is, the best Civilization because it removed a lot of the obstusiveness of Civilization III. It made the game easier to play rather than making the game easier by simply streamlining everything
. Many people who previously were turned off by the complexity of Civ-style titles loved Civilization IV because of this, and even I prefered the Civilization IV way of things. It was simply a better package, although frankly anything with Leonard Nimmoy voice over is better than something without it.
Now, I may be jumping to conclusions here, sure. I'll freely admit that everything about Civilization V sounds, and looks, utterly fantastic! However, so far everything about the game is also raising those Red Flags my PC-centric-gamer-brain has been forced into evolving to see a mile away to prevent myself from buying watered-down console-style trash that is flooding the PC platform.
Accessability is the death-cry of nearly every single major PC series. Accessability means, as has already been mentioned, at worst a multi-platform release, which means that the game is dumbed down or changed (see C&C3, Supreme Commander 2, etc.) to ensure larger volumes of sales, or at best it simply means the game is dumbed down for the PC and results in a watered-down version of the previous installments. Being as Civilization IV streamlined basically every single aspect of the game, there's very little left that can be properly streamlined without reduction and thus I highly doubt they mean that they're improving on the near-perfect Civilization IV, meaning by extension that a more 'accessible' Civiliztion V will most likely mean a dumber Civilization experience over-all. Playing into that is the changes to the Diplomacy screen by masking the available information. This removes intelligent decision making. By extension, I predict we'll see a simpler version of the Civilization we know and love.
Believe me, I hope I'm wrong.