Ok, I'm Waaay behind on reading this thread (I'm currently at comment 4760 as I type this) so, this might be very out of context.
I see two pretty serious issues with this discussion that are getting ignored.
1. This is a biggie. Most players have more than 1 DM. They have played with other DM's and will play with more in the future. They are not judging the DM based entirely on that DM alone but by their experience with other people in similar situations. Meaning that advice to "trust your DM" is a much higher hill to climb for a lot of players. Law of averages says that some DM's are bad, some are average and some are good. In probably equal amounts. So a given player has been burned, and probably repeatedly, by this advice - they've trusted the DM/GM, only to have that trust broken by bad game masters. Which is going to lead to players being far less open to just "trust the DM" advice in the future.
And this leads me to my second point:
2. Good and Bad sometimes don't look very different from the perspective of the player. Because games like D&D rely on "black box" DMing, where a lot of information is withheld from the players, the events of the game can look virtually identical regardless of the quality of the DM.
Take the example of the unbribable guard. Sure, it's an old chestnut, but, it highlights what I mean quite nicely. The Bad DM makes the guard unbribable because the Bad DM wants to railroad the players into a specific path and allowing the party to bribe the guard would allow them off the rails.
THe Good DM, on the other hand, has decided beforehand that the Unbribable Guard is a member of some order, or has taken some oath or whatever reason, and has made the guard unbribable.
But, and here's the kicker, the players can't tell the difference. Good DM and Bad DM look exactly the same here. After all, the Bad DM can just as easily claim that the guard belongs to some order or has taken some vow, or whatever, and railroad the party. The Good DM isn't railroading the party. Totally not what the Good DM wants. But, from the player's perspective, there's zero difference.
This is why we keep arguing about this idea of the "objective" DM being a fiction. Because, in play, Good or Bad DM often look exactly the same. Even though the Good DM would absolutely recoil at being called a Bad DM and would completely reject the notion of railroading as an intent (after all, no railroading was intended at all - it was a "natural consequence" of the setting), from the player's perspective, there's simply no difference.