DF simply doesn't display information that players actually need to know. It's also not consistent enough for players to guess.
Why are mining, channeling and cutting under a menu opened by pressing d? Why do the workshops have the keys assigned that they do? There's no internally consistent logic that a new player can rely on, they have to memorize a lot of arbitrary stuff in order to play at a reasonable speed. This is punishingly boring.
How do players know what is causing stress and what is supposed to relieve that stress? They mostly can't, unless they look at the wiki. Where do they learn about skill degradation? They mostly don't, unless they look at the wiki. How do players learn about reasonable fortress design & pathing? They basically don't, unless they look at the wiki. Etc. So, so much actually important information that is vital for effective in-game decisions isn't in the game. This is crap design, it's put off everyone I'd introduced the game to, and it's why I simply don't interact with large parts of the game.
At every point the player has to make a decision, the important considerations are "What information is relevant for this decision?" and "Is this information clearly presented in-game and easily accessible from the screens where players make this decision?". DF frequently fails to display relevant information at all, and even displayed information is hilariously opaque or not clearly relevant to situations where it is relevant.
Over the past few updates, the parts of the game that don't require massive out of game memorization, or specifically changing my playstyle to avoid punishment and fort loss, have shrunk tremendously. That's the opposite of what a game should be. Players need to know the information that is relevant for the decisions they are making, and they need to be able to play a game in a way they find fun.
ETA: Since Toady and ThreeToe apparent didn't know that werecreatures were aggravating and unfun - will infiltrators be disablable? Visitors aren't, which is bad enough (who wants to be completely incapable of stopping randos from wandering in? It's historically inaccurate, and it's bad design that potentially overrides player decisions. Gate guards are a necessary missing feature from the visitors arc), but if infiltrators can't be turned off, that's terrible. At the very least, new players will need a detailed overview of what infiltrators are and how to spot them. They also need to be always noticeable in some way. Not being able to spot them would be...not good. Gameplay features that can disrupt or reverse player decisions and aren't configurable are always a bad idea.