The game is supposed to be hard, but if you at all know what you're doing it's very easy to keep your fort well, and the only real risk of losing your fort is from you intentionally doing stuff that puts your fort at risk. You literally can defeat entire enemy armies by capturing them all with cage traps, for example.
This I can forgive.
Dwarf fortress is all about the crazy stupid ideas you can come up with after all. Want to build any interesting structures? Prepare for your dwarfs to get stuck every conceivable way one could possibly get stuck trying to build a simple wall. It can be incredibly tedious to accomplish something that ideally shouldn't take more than a few simple commands.
All of this I could live with. The performance without fail is what eventually kills my will to play. Want to do cool stuff with magma? Watch the game slow to a crawl. Want to run a big society? Watch the game slow to a crawl. Want to do anything remotely interesting? Watch the game slow to a crawl.
People go to obscene lengths to keep their performance, such as generating atom smashers that will 'delete' unwanted stuff from their fort completely, so the game stops wasting energy rendering 5000 rocks and how each dwarf is reminded about their childhood traumas as every rock reminds them of how their father died from a falling rock.
This game is so close to being great but falls short at the very last mile because the basic gameplay is fundamentally flawed. This is a simulator first, game second and it shows :(
I mean, the pipe performance fix took one factorio dev half a year. I feel like having no forward motion apart from performance for that long might demotivate tarn, and that was just for one subsystem. In a game which already invested in multithreaded performance.
I bought the best single-threaded CPU perf I could find at the time (https://www.cpubenchmark.net/singleThread.html) and put it in the smallest case that could support it.
End-game Crusader Kings 2 takes two seconds to simulate each day on my 2017 Macbook Pro. My desktop PC can simulate half a year in that time. I can also play on the largest Stellaris galaxies.
Sooo much more enjoyable when you can run a simulation as fast as you want. Now I can actually finish games instead of bailing at mid-game when things start to slow down.