They are correct in that thinking, but Bitcoiners may be in error in assuming Bitcoin will inevitably replace the dollar, as the Chinese are much better positioned to determine their currency is used in trade payments.
It is in MoE dominance that monetary hegemony is gained.
BTC being increasingly seen as and used primarily as a speculative asset does not challenge directly challenge either the dollar or the Yuan as they compete for global MoE dominance.

Indeed. They would probably describe it as being for criminals more often than a bitcoiner.

I was thinking about how they imagine bitcoin is for a bunch of crazy anti-government types and illegal use cases. So maybe it's not that they think bitcoin is a threat to dollar. 

It's that they think Bitcoin exists to threaten the dollar.