Anti-British propaganda from both world wars is very much about the piracy and what that supposedly proves about national character and the way we conduct our foreign policy. This, for example is fairly typical:
Well it seems that the challenge has been fulfilled by the Spanish...
Britain never establishing her naval dominance might be a big step; perhaps she gets dragged into multiple continental wars? So she instead remains a mass employer of privateers late into the 19th century.
Or maybe if we get a British Napoleon who uses the RN to plunder Euro-American states.