Let's make an analogy:

For thousands of years, states have used gold. For thousands of years, thieves and mafia have used gold. If we consider gold to be a good thing (at least before Bitcoin), does that mean that thieves, mafia and states are good?

Obviously they aren't. This is a fallacy.

It doesn't matter if states use Bitcoin. That doesn't make them good at all. They are just using a good thing for (very) bad purposes, as usual.