I’d really like to know. I keep seeing arguments about player choice and agency and railroading. And for the life of me I cannot understand why anyone would defend railroading. Any advocates of railroading willing to explain why it’s good to do?
I haven't read through this thread, but off the top of my head I can only think of a handful of reasons why someone would need to use the railroad plot device.
The Players are Children. If your players are all under the age of 10, a fixed linear plotline (my definition of "railroad," yours is probably different) can really help keep the evening on track. You want your players to have fun playing make-believe, but you also want them to make it to the rest of the story before the end of the game. Thus, you will probably need to deploy some manner of a "railroad" plot. Not because you want to restrict anyone's fun, but because you want them to have a complete experience.
The Players are Behaving Like Children. Some players forget that the DM is supposed to be enjoying the game as well, and try to make things as difficult as possible for the Dungeon Master. If your players are the sort who will narrow their eyes, smirk, and say "Oh we will just
see about that, Mister DM" whenever you introduce an adventure hook, a railroad might be the only way to get them to the dungeon in the first place so that the adventure can begin. (It might also be the only way to maintain a healthy blood pressure.)
The Story Is Too Convoluted. We've all done it before: created an enormous, interwoven, tangled mass of plots and subplots and intrigue and interwoven factions, and thrust it all upon our players in a single lump of exposition. And even if your players are the sort who will hang on to your every word, using yarn diagrams and post-it notes on the wall behind them, chances are they are going to miss that Obvious Hint (one of several) and miss a crucial part of the adventure (one of several). Unless you gently (or not-so-gently) direct them onto the right path, you can look forward to a long and frustrating night of players saying "ummmmmmm" to each other and staring at you expectantly.
We All Think Differently. I'm ADHD, and I'm just one of a handful of neurodivergent players in my gaming group. (Two of us are ADHD, another is dyslexic, and one is on the Autism spectrum.) I find myself wheeling off onto tangents easily, and getting distracted with things that don't matter, and getting frustrated with players that don't pick up on the things I think are obvious. A linear plot can sometimes be useful to keep
me on track, and to ensure that the framework of the story stays intact.
TL;DR: railroads aren't everyone's cup of tea, but I think they have their place at the table.