Honestly, given how masochistically some gamers chase max-difficulty wins, I wouldn't be surprised if a game in which only 1% of seeds were winnable would be appealing to some.

But it would definitely diminish many gamers' enjoyment, as you say.

Dark Souls is an example where some players just aren't interested in the difficulty (even though the game is winnable), and some players relish it. Perhaps "win % for the median player" and other populations are more practically useful lenses for the discussion of general enjoyment.