This. The actual amount of FPS our eye's can perceive and our brains process varies wildly between individuals. Fighter pilots can usually describe a single frame presented for 1/250th a second, but there are also segments of the population that struggle to differentiate much above 24 fps. Most people generally won't notice increases over 60 or so, and it won't get choppy for them until much lower.
This is based upon a false assumption.
Yes, the average viewer can't see a single frame that is going at something like 60fps, but that doesn't mean that the player can't notice when the game is moving at nearly half the speed. Keep in mind, the typical dwarf has to wait nine out of ten frames, so even at 100 fps, they're only actually moving at 10mps (moves per second), which is well within human visible range. Even if they weren't, you'd easily see the difference between a dwarf flying 50 tiles in a given time frame and only moving 30, or dwarves building only half a tower in the time it took them to complete an identical tower before.
Anyway, what amount of FPS a player is willing to put up with varies widely from player to player.
Players who tend to focus upon military and players having to dynamically react to threats tend to demand higher FPS, because they want to sit there and enjoy the "action", and the "action" is very slow in coming at 10 FPS, requiring waiting 10 times as long for their dwarves to stop drinking and assemble before they can be thrown at the enemy.
Players who focus upon megaproject construction tend to be used to an FPS of 1 to 5, anyway, because you're not getting any better than that when you have a 100z-level cavern excavated in a 5x5 embark and make all your civilian housing out of giant stalactites. Players who focus upon large designations and building tend to be able to cope with largely automated fortresses and simply designating for an hour followed by leaving the game to run itself for several hours (or even just go to sleep) without bothering to come back to the game for a long while. They're not playing for the action, anyway, so they don't care if they "miss the action". These players, obviously, are more likely to just wall off the cavern FBs and let the goblins fall into automated magma traps.