The problem is, a lot of people come in hearing about the awesome stories from games like Minecraft or Starcraft or whatever else has DF references in it and expect to find a nice game that has a typical learning curve, and you can hit the World 1 slot and be in your stone castle after a few hours.
Then when they can't even figure out how to dig after 20 minutes, and their first few fortresses get thrashed by a forgotten beast and they get that feeling of no control when some stupid dwarf tantrums instead of building the wall that keeping the troglodytes out they get frustrated and complain on the forums.
The problem I see is that Dwarf Fortress is unique in that you don't directly control any character, and unlike many other games with a similar concept (RTS's), the dwarfs can refuse to do what you want. The typical player coming from Starcraft or flash castle-building games will be very confused when the tell a dwarf "Go dig there" and the dwarf gives them the middle finger and gets some booze with the fisherdwarf and expedition leader instead. In fact, eating, sleeping and drinking are non-existent in most strategy games. Then they finally get that dwarf to dig out the entrance hall and find 20 different types of stone, ores and gems and they don't realize that they all do the same thing with a few exceptions... DF gets confusing, quickly. For instance:
Typical strategy game:
Worker states: Working, idle
Building materials: Stone, wood
Buildings: Base, mine, sawmill, windmill, castle, barracks
Valuables: Gold, gem
Power: Build windmill next to building
Dwarf Fortress:
Worker states: Working, idle, sleeping, eating, drinking, partying, on break, tantruming, recovering in hospital, doing something else, dead
Building materials: Marble, olivine, orthoclase, micrcocline, etc. etc. Maple, mahogany, featherwood, tower-cap, nether-cap, goblin-cap, etc. etc. etc. Copper, bronze, steel, bismuth-bronze, tin, adamantine, etc. etc. etc. Forgotten beast soap, crocodile fat, kitten bones, etc. etc. etc. etc. etc.
Buildings: Armor stand, table, chair, butchery, masonry, carpenters workshop, alchemy workshop, farmers workshop, jeweler's workshop, still, farm, floodgate, door, lever, gear assembly, windmill, waterwheel, horizontal axle, vertical axle, etc. etc. etc.
Valuables: Gold, silver, XxBloody Pigtail SockxX, really anything has a value and can be sold.
Power: Build a windmill (make sure you have wind in your embark! Oh wait, you didn't check immediately after embarking? Sucks for you), or build a waterwheel in flowing water (make sure it's flowing, not still! How do you tell? Go check the wiki or something!), then build axles out from it's gear assembly, remembering that each axle eats 1 power and each assembly eats 5, then get it to the pump.
So yeah, DF is much more in depth than most other strategy games, and while some of that depth is surface only (most all rocks are the same), some is not (what the hell are my dwarves doing!? Build that wall, stop partying! How do I make them stop partying?!? Oh, the goblins got in you dumbasses! Party in hell!)
Of course, if there were more DF 2010 tutorials ( a lot of newbies don't use the old ones simply because they say that they're from 40d, even though the basics haven't changed) the situation would be better, but until someone just makes a comprehensive 31_xx tutorial we just have to point newbies towards the wiki, old tutorials and gameplay questions sections.
EDIT: Stop posting so fast!
The farming deserves it own tutorial at this point, pretty much. I've never realized why some people get so hung up about it. All you really need is a farming room, a cistern which is a little bigger than the area of the farming room/7, a door between the water source and the cistern linked to a lever, and a door between the farming room and the cistern linked to a separate lever. Fill cistern to 7/7, close that door, open door to farming room, make mud, close that door, refill cistern, use for wells. Grand total of 2 doors+6 mechanisms, or 8 rocks. But whatever.