Again, this is just a straw man. People are trying to make a naturalistic world, a model sufficient for a game. They aren't pretending to be a computer that simulates reality. But in reality, things that happen are still bound by logic. Even improbably events, when you roll them back, have a logic and cause and effect that makes sense. All most people are saying here is that they try create a gaming experience in the world bound by cause and effect and naturalistic reasoning. But it is more than just that. They try to run NPCs as if they were real, operating on real personalities, motives, etc. It is the difference between starting with what the villain wants to do to the party, for example cut them off before they reach the Duke's manor, then figuring out what steps that NPC needs to take in order to cut the party off, versus deciding that the NPC and his men just so up because it is dramatically appropriate. Also nothing in the former precludes rolling dice. Most GMs like this will rely on randomness from time to time to help achieve a better sense of verisimilitude. They aren't obligated to but if you follow discussions by people who play these games you see random rolls form a large aspect of the style of play (but usually as tools, not as requirements).
And to be clear, nothing wrong with the other approach I mentioned in the example. Like I said in my example about men popping out of walls. I've done that when it is dramatically appropriate in some games because I wanted to emulate a thrilling Cheng Cheh movie. But I have also been in more naturalistic games, where something like that doesn't happen because it is appropriate, but you make it something that could happen provided there is an appropriate set up (in which case, if it does happen, it is likely to go down very differently and be easier for your players to detect or hear about ahead of time).
I don't even think sim-immersionist is the best way to play. As I have said, I often run games that are drama and sandbox, while the rest of the time run games that are monster of the week. And I avoid language like simulationist. But I don't understand why folks in these threads are so bent on proving this style doesn't exist or is somehow absurd when people clearly engage in it all the time