This sounds quite reasonable! But if all a knife needs is a sharp blade, there's little to be done in the way of limiting its specific uses.
Also, do cryptocurrency bosses ask the community to shape Haskell in the way suitable for them, e.g. in the core libraries or extensions? Or do they just produce libraries for their own use?
Its more like, would you enjoy your weekend foodball game if you knew that stadium was build by slaves. Theres nothing bad in stadium it self, but the circumstances how it came to be are not acceptable for you.
I.e., it's a call to the knife makers to stop making their knifes to the specs of mob bosses, not a call to ban knifes.
There are plenty of precedents for this kind of action, e.g. pharmaceutical companies refusing to supply chemicals for executions. (If were already going all life-and-death with the analogies)