Repression, tradition and overwhelming support from the top only carried a state religion so far. Despite its messy origin and flawed construction, the Vulcan Faith had everything it needed to remain the undisputed belief in the Vulcan Empire.
There was only one issue.
The god it is centered around looked like a normal human.
This was a discordant element that conflicted with the strong anti-human bias of the militant dwarves. This little detail was so out of lockstep with the Vulcan Empire's culture that it had always led to a lot of questions even among the citizens who never heard about the Dwarven God Cult.
Now that this alternative vision of Vulcan spread throughout the entire dwarven state, many average dwarves now had a better at their disposal.