Lanefan
Victoria Rules
Yes, though quite likely with different players plus the one who said yes.But how many DMs here would actually overrule a majority of their players? If you wanted to run a campaign about being in the Roman Republic, and 5/6's of your players said no, would you run the game?
That said, I hope I'd be a better judge of who to invite in to begin with than to blow the call on 5 out of 6.

This one depends on why the players are disagreeing with the rules/rulings.If you say that the stealth rules work X, but 5/6's of your players say it is Y, do we really think that the DM is going to insist on overruling their table, or do we think there is going to be a discussion as they try and convince the rest of the table to agree with them?
IME players far more often disagree with rulings (or rules) that are to their characters' disadvantage; and after listening to what they say I-as-DM then have to try to assess whether the disagreement is a legitimate issue or just an attempt to make things easier on their characters.
If it's a legitimate issue, or they can show me it's legitimate, discussion continues and I'm open to suggestions.
Put another way, maybe it's losing traction because players feel more entitled to disagree?I think this is why the idea that the DM is actually the ultimate authority is losing traction. Because the authority the DM is deriving is from the rest of the table agreeing with them. If the table disagrees with them, then the authority vanishes.
My take - with which not everyone will agree, but that's nothing new
