I've been thinking about that a lot, about these games that uses procedural generation. I've been playing a game on Xbox where "random" events occurs and you have to act accordingly. I've noticed the game wasn't fair or even winnable. That random event striking me that moment of the game, there's no way I could be prepared to deal with the situation (frostpunk, I think is the name of the game). When I released Qubes, my game, I made sure every level was winnable. So when people write me emails telling the level doesn't have a solution, I know for a fact that it has, the player just couldn't find yet. That's a nice article and I appreciate you sharing.