EU and UK are toothless loyal US dogs. They doesn't have own decision making process now. The point here isn't is Maduro good or bad, but the point is they are breaking all democratic principles.
Having Bitcoin will not help Maduro anyway. He will need to convert to fiat at some point. And all cryptos are what 120B? This is nothing compared to world finances and needs.
Thus, Washington intends to prevent the country's authorities from "plundering the wealth of Venezuela for their corrupt purposes." Bitcoin is unlikely to be a panacea in this case.