Even tho, that DF is alpha, and lot more features will be added, its [Dwarf mode] already much more complicated than a "simple" roguelike.
That could be it - there's just so many more items to keep track of.
Also, I think the fact that the default DF ASCII uses so many weird, non number or letter symbols, as basic things, and letters are the relatively uncommon animals. So many unfamiliar things as opposed to just learning a bunch of meanings for letters and punctuation marks, is kind of like learning the names of a bunch of Europeans you don't know, as opposed to learning the names of a bunch of Asians you don't know (assuming of course you're American).
Interface wise, what I would love to see is a little (or big) toolbar just below the main play screen with icons for all the things that are now on the commands menu (obviously this could also use some streamlining) and clicking on one would open its particular submenu below that...clicking another would open up ITS submenu and close the old one...and so on. All this with mouse support would mean you can just click the "hammer and bricks" icon to open up a tray with all icons representing particular buildings...click on the dwarf at work for the workshops...click on the dwarf carving a statue to select mason's workshop, and then use the mouse to place where you want it on the map, and select the material from a popup menu.
And so on. Another nice thing mouse support could add would be to roll the 'q', 'v' and 'k' commands all into one. Just right click on a tile to get a little popup list of who and what is in that tile; if it's an item, you can forbid, reclaim, mark for dumping or melting, or whatever...if it's a unit besides one of your dwarves, you can mark it to be hunted, captured, killed, whatever...if it's your dwarf, you can get the dwarf profile to see wounds, inventory, assign jobs, etc.
Anyway, that's all wishful thinking. It would make the game run much more smoothly, but tbh, adding more gameplay features is a way bigger priority for me than improving the interface, which, although admittedly terrible, is totally usable given a little practice, and I really have no major problems with it. Maybe mouse support like I've described could be modded so that those who want it can use it - anybody know how? (I don't)
As for graphics...I think the usermade graphic sets are just fine, and having ASCII as default is too. It WOULD be nice to have support for graphics built into the game, and maybe have a list to pick if you want ASCII, or one of the major popular tilesets (like in Angband) so that it would be easier for people to make the game look how they want, without editing all kinds of entries in weird text files.
Lies. The first time I ever played an ASCII game I thought it would be mind-bendingly difficult to understand. It isn't, at all. It's a matter of familiarity and learning how to use a 'l'ook button (or some other variant, all roguelikes I have ever played have something along those lines).
Like I was saying though - DF's ASCII is off-putting even to some people who are hardened roguelike players like me, just because it uses so many strange unfamiliar symbols, and so many of them.