I do not said DC is a RPG, I said it has both, RPG and of course most of all strategy elements.
But I believe that it give more pleasure & fun to "see" you own hero(in) ingame ! I feel very sad to not know how my hero(in) look like playing a game! And 'for me' it gives me a very different feeling with or without an avatar !
Walking around in the Raven is more than only using the Dragon Stone, not ? And what about the conversations with NPC's ? Without an avatar ? Aaaarrggg ! Aahooee !! Down with that !!!
Only playing a pure puzzle game like the Mist games don't require a avatar (for me).
All right, let's say there's a ship you can walk around. Here are some things Larian would have to think about in that case:
How big is the ship?If the ship is too small, it runs the risk of being unimpressive and pointless. If the ship is very large, that's resources you need to spend making corridors and rooms.
What would you do when wandering around the ship?What can you interact with? Are you only there to look at the pretty ship? There's only so many times you can look at the inside of the ship/the pretty view before it stops impressing you. In Flames of Vengeance, How many times did you walk everywhere instead of using the teleporters? I'm sure you stopped walking at some point.
The only new unique elements that would keep changing would be maybe a few graphical changes as you get upgrades, and conversations between unimportant NPC crew members. (Important crew members would be found at destinations, not in the hallways.)
All right, so now there's a bunch of generic NPC's having conversations in the corridors of your ship, reacting to your decisions. That's more budget you need to spend on voice acting and less on other areas of the game. Larian's said repeatedly that this stuff is really expensive, and they're not a big AAA game company.
Yeah, it'd be great to have that, there's no question. But it's still all extra stuff which isn't part of the gameplay. It would have been great to leave Aleroth and wander the area outside in FoV. But they didn't have enough resources to do both the outside and the inside.
It's NEVER as simple as "the engine could support it, therefore that's a reason to have it in". Granted that the demo movie isn't likely to be reflective of the final game, but all the conversations with NPC's, the player had no human avatar at all. Almost all strategy games don't have a specific human avatar - the only one I can think of is Starcraft II.