I say this as someone currently developing a vast space game using procedural generation: The danger with procedural generation is "remix boredom." The user can feel, "Oh, this is just a remixed variation of the same stuff."
The reason why we don't feel that way about the real world, is because the real world doesn't just have "remix procedural." You have to have some player-significant emergent effects coming out of the procedural generation. You see this in Minecraft. You even see it in the 1st generation of the original Elite game. The player's interest in your procedural world is directly dependent on how deep these emergent effects are. (So the emergent effects can be shallow or deep, with the corresponding amount of interest from the user.) (Which is why my procedural generated world primarily exists to support a procedural generated technology tree.)
The reason why we don't feel that way about the real world, is because the real world doesn't just have "remix procedural." You have to have some player-significant emergent effects coming out of the procedural generation. You see this in Minecraft. You even see it in the 1st generation of the original Elite game. The player's interest in your procedural world is directly dependent on how deep these emergent effects are. (So the emergent effects can be shallow or deep, with the corresponding amount of interest from the user.) (Which is why my procedural generated world primarily exists to support a procedural generated technology tree.)