Necropolitan
Hero
That's completely false.If everyone in the table ended up not following the premise of the campaign then the premise of the campaign must be wrong then. Sure if 1 or two are against it then it's fine to reprimand them fromnot following the path, but if everyone's pushing left then left is where the campaign will go.
The DM is the one running the campaign, the DM decides which way it goes.
If you don't like how the DM is running the campaign and can't convince them to change it then find another DM.
Instead you're trying to force DMs to run campaigns they don't want to run.