So, I only read the first three pages, but I'm still going to post. You can't stop me!
I think the reason commercial developers haven't made like ten Dwarf Fortresslikes already is the design philosophy. If your game has a budget, you're probably hoping to get some money out of it inside a reasonable timeframe. So you think of a finished product you can get done in time, and make it. Then you move on to the next project.
Whereas DF has... well, everything. If something exists in the world, the plan is to allow the player to interact with it in every possible way. For example:
Bloat328, IMPROVED SEASHORES, (Future): Coastal biome designations, grabs, gulls, washed up jelly fish, ability to skillfully build sand castles in wet sand which can be worn down by waves, shells, washed up objects from distance civilizations that are on the body of water, seaweed, tidepools with anenomes, driftwood interactions.
So, we'll be able to make sand castles. And then take a bit of driftwood, and carve little wooden soldiers for the sand castle. And if we ever get the magic system running, there will probably be a sand castle fairy or something with a magic aura that makes sandcastles spontaneously appear around her. There will be absolutely no point to any of this, Toady's just putting it there because he
can.
This will no doubt lead to some spectacular "Holy shit I can
do that!?"-moments, but I don't think it's really a feasible money making strategy. DF has been under constant developent for a couple of years now, and it's nowhere close to being anything like complete. In fact, it doesn't look like it can ever be properly complete. I'm sure that by the time we get through all the version one arcs and the post-version one arcs, to the Full World Simulator era, something new will have appeared that could be implemented. And there's really nothing
outside the scope of the game. Steam power might not make an appearance in the vanilla game, but modders are still going to want to be able to do it. Same for electricity, nuclear power, space flight and geological simulation for dropping the freaking moon. Actually, that last one could come up in the vanilla game, dropping the moon appears reasonably often in other RPGs.
Dwarf Fortress as it is now isn't really a commercial-grade game. There's nothing to do in Adventure Mode. As there's basically no graphics, it's really difficult for new player to get into the game. Once the dwarf count goes up, it starts having serious performance issues on most machines. While the Dwarf Fortress described in the Dev Notes will certainly be the Best Game Ever, we're not quite there yet, and unlike lone indie developers, giant corporations constantly lose asstons of money for every moment they spend making the game instead of selling it.