Vikings were pirates*, and we've had plenty of Viking movies. I'm reminded of Gene Roddenberry's remark that Star Trek was a wagon train to the stars. Just take an old genre -- one that may be a bit worn and in need of a breather -- and transpose it to a different setting.

And speaking of space "westerns" ... well, I haven't watched that kind of film for years, but aren't there plenty of piratical types in sci fi films?

Not all pirates have to have eyepatches, wooden legs, and a Hollywoodized Elizabethan English accent.

*Yeah, yeah, I know: Vikings were a lot of other things besides pirates -- but raiders and pirates are homeground for Viking lore in the movies, largely because that is how they primarily impacted the (slightly) more civilized peoples of the British Isles and France, and the slightly more civilized victims of Viking pirates raids, in the end, were the people who wrote the history books.