I definitely disagree the game needs any sort of built in tutorial. We have plenty made the community...on the wiki, on the forums, on YouTube. A better solution would to make these resources very obvious to the player. I saw the Wiki link snuck into the ReadMe, but honestly, who actually reads those? When someone opens "Help" they should be presented with a series of links pointing them elsewhere.
Anyways, I'm going to split this up like a previous poster did into "What turned me off in the beginning" and "What turns me off now", as I think the distinction is important.
Beginning:
*ASCII graphics coupled with the low color amount. One or the other I could probably deal with, but both made it very difficult to understand ANYTHING going on. I remember the first time I noticed vermin, as I kept wondering what the fuck these weird colored commas and apostrophes were doing blinking in and out of existence. Finally I was able to pause just in time to see it was a fairy flying around. Cute.
I understand the difficulties Toady has to overcome when it comes to graphics. On the one hand to stop and focus on them would eat up a lot of his time. However, to simply open it up to the community would also wrestle some pretty important control over the game away from him, something he clearly does not want (nor should he).
And yet despite all of this, the ASCII graphics and limited colors are the #1 reason people are being turned away from the game. It's mentioned in the first line of any description of the game ("...and if you can get past the Matrix-like quality of DF...") and is definitely both a turn off for people who DO know what they're doing and downright scary for people who DON'T know what they're doing.
*Beyond that? A clunky interface that seems to change its mind far too often (Wanna close this screen? Try Space. NO WAIT I MEANT F9!) and that overcomplicates an already overcomplicated game.
*Finally, the lack of any meaningful description as to what is what in the world. When I first started out I had the Wiki open in another tab constantly searching info about every stone I found because I had absolutely no idea what was important and what was not. Repeat this process for damn near every item, building, and character. Also, as someone who hasn't taken a geology course in his entire life, it surprised the hell out of me when I wasn't striking any "iron veins". Little did I know that shit came from ores that sound like Pokemon.
Now, as a "seasoned" DFer:
*No goal or incentive to do anything most of the time. Hard to fault the ALPHA of a game for this, but if you're asking what turns me off, this is a big one.
*Clunky Legends mode. I LOVE Legends, but in its current form it's almost impossible to follow even one character around without getting lost. And what kills me is that it is SO OBVIOUS how AMAZING it would be if it followed a "Wiki" style formatting. Oh, Soandso moved to Placething? Awesome! Click on Placething to see what it was like and where it was. Oh the battle of Squeezingthighs took place here? Click on that to get a detailed view of the battle. Oh hey, there's Soandso leading the battle!
*90% of all locations are "boring" or, in some cases, entirely stupid to settle on. Without magma your metal production will crawl, and your glass production probably won't exist. No flux? No steel. No sand? No glass. Lack of adamantine = lack of awesome weapons/armor/items and also lack of some pretty important "end game" difficulties. Found an awesome place nestled in the mountains or on an island? Get ready to play Dwarf Fortress: Survivor, as if others can't "reach" you, then you may as well be all along in this world. No traders. No sieges. Nothing.
So people spend countless hours trying to get the planets to align and find the one suitable place where a lot of those features cross. And as I and many others have noticed, it's quite rare for all of this to occur in a playing space less than 3x3...which leads me to...
*FPS problems. Number one complaint as a DF veteran. It is THE reason I quit fortresses basically 9 times out of 10. I have two rigs, neither one of them bad. The laptop has a speedy processor and lots of memory to go around, and the desktop, though old, has plenty of decent parts. My desktop can play L4D on medium settings, it can run Fallout 3 on the low ones, and basically any game released before 2008 it can run high.
And yet god forbid I have a fortress larger than 50 dwarves, else my FPS is cut down into the 40s on a good day, and into the single digits when a trader comes.
Anyways, this post is long, but hey, a developer of the game asked me an honest question, and I think I owe it to you guys to give you an honest answer.