Exactly. One of the chief benefits of BitCoin is that you can act in an anonymous manner if you perform your transactions in a careful way. This means it is inherently open to being collapsed by a powerful actor that has the resources and will to attack. Certainly a state but I suspect a relatively small group could do the same.

Being found out as the source of an attack is the biggest deterrent. Without the deterrent the temptation for a vested interest must be a magnitude higher.