I don't have much time to reply to all the points made earlier, but I think one big difference between the Golden Era-RPG's (late 90's) and nowadays RPG's is the way the world seems to be closed.

The Might and Magic serie was pretty action based, that true. You'd spam the attack key to cut through hordes of mobs. Dialogue was pretty much inexistent: guy asks you to kill some mobs, and rewards you with money.
But Might and Magic offered a vast, open world. You had a main plotline, but you could go visit dozens of unrelated places before being done. Exploring the whole world took dozens of hours.

Baldur's Gate did even better. Not only it offered a vast world, with a rather large amount of sidequests and several areas to explore unrelated to the main plot, but it also did a heck of a job with dialogues and immersion, two things that IMO were badly lacking in previous RPG's.

Arcanum and Fallout were mostly similar. The world seemed huge, and believable. You'd meet people who would do stuff on their own, talk to you about random events.

Since then, something has changed.
RPG's decided to cut down on the "useless, vast world to explore" thingy. Worlds don't feel living anymore.
That's especially true of DA:O. When you visit Redcliff, all doors are closed, except for a few ones. And if you can open it, it means there's a quest inside.
There's no useless area to visit, and you can't get away from the main plot. Characters who aren't involved in a quest don't have anything to say.
You arrive in a village? Check out which doors you can open to know what you have to do. And if you can loot a body, it means it's quest related too.
That was the same thing for ME, NWN1 and 2, KotOR1&2. Maybe the 3D is to blame. But I'm pretty sure it would have been easier to create a living world with NWN1&2 toolsets than it had been for BG1 or Fallout.

And oddly, the same applies to JRPG's. Have a look at the Final Fantasy franchise. Those games have always been quite straightforward. You start in point A, go through points B, C and D until you arrive to the big bad guy. There are a few sidequests on the way, a few choices to make (who am I going to date at the Golden Saucer?), a few hidden stuff to find. Until FF9, despite that, the world at least seemed open. You'd be running around doing stuff, in a completely straightforward fashion, but you wouldn't notice it.
Then, FF10 and 12 were released. Both were terribad (IMO), because you immediatly felt that you were litteraly running on an endless road, from point A to point Z. Sure, at some point you'd get the ability to go back to point D, or M, but it would still be the same endless road. You'd have to watch Tidus running for hours, from one side of the screen to the other again, and again and again. A real immersion killer. The same was true of FF12, though it was nearly as bad.