Agreed. I hate railroading. I am just of the opinion that sometimes players try to railroad the DM!
Pretend for a moment there was a group of brigands disrupting the productivity of serfs, agriculture and commerce in medieval Europe. I would imagine some verisimilitude requires a response.
When younger, we used to laugh at villainy in the game. But really never got off on tormenting innocent NPCs. It was more goal-driven. Rob a manor, steal some gold and magic, fight a feud, run from the law if you get caught! We always had someone chasing us it seemed and it was fun.
However, that was what we told the DM we wanted. In the OP case, someone who has designed a heroic adventure with the expectation of LOTR is getting Grand Theft Auto. That sounds disheartening and less than fun for the DM.
Yeah, if the DM doesn't want to run a game of GTA, it's not a winning situation.
Verisimilitude is great, but it's also important to maintain genre consistency. genresimilitude. Players, over the course of a game, or maybe based on preconceptions, have an idea of how their actions impact the game world, even if they would have a different impact in the real world. If the DM moves too quickly to change these expectations, it can be jarring and disruptive, and lead to conflict at the table that would have been better addressed out of character.
An example. Say the players love having their characters jump off of absurdly high stuff, but always land feet first, like a character from Underworld. It's jarring to the DM, but they allow it, and so, if the characters make an acrobatics check, they can jump off 200 foot tower, stick the landing, and keep going. One day, the DM shows up and says, "You know what, I'm sick of this




. You can't go around jumping off towers and not getting hurt. IT MAKES NO SENSE!" And so the next time a PC jumps off something high, the DM says, "You fall. 200 feet. Roll 20d6 damage." The DM ain't wrong. Those are the rules from the book. But they've also suddenly shifted the expectations of in-world consequences in the game and pulled the players out of the genre they thought they were playing in and into another one. They'll fight.
I've had things like this happen at my table before. Best to ease those consequences in gently, is all I'm saying. Players don't need to know the exact consequences of their actions, but they should at least know that the game world is reacting to actions along a certain axis and that there might be SOME sort of consequences for that. (Another example. Players routinely cast fireball, frequently in places where things catch fire. But the DM never worries about it and nothing ever does. Then the players cast fireball in a redwood forest, and the DM, rightfully so, says, "Oh yeah, also, I mean, fireball in a redwood forest. Sorry Smokey." Players would be miffed, because magical fire, up until this point, was treated as not really interacting with anything in the world other than hp-sacks. Nothing ever catches fire in Baldur's Gate when you drop a fireball on some fools in the woods.)