@Malintex_Terek:
It's not about space, it's Oda going overboard with everyone having a Devil Fruit and everyone who is not a Marine being a pirate in some form or another. I can finally understand why AK_of_Troy hates this series if Oda introduces 'space pirates'; it essentially means he's gone senile with his creativity and applies a flat standard through means of a copy-pasta plot device onto every character.
Not unlike a certain show called Pokemon, in fact.
If you haven't noticed, there's a certain relevance to the devil fruits.
Logias are only held by people of Whitebeard's crew and high-rank Marines, the exception being Crocodile and Eneru, but Eneru doesn't really count and that only supports my theory of Crocodile being a former part of Roger or Whitebeard's crew.
Zoan are only held by bodyguards and people associated with the WG, the exceptions being Chopper and Lassoo. Though in Chopper's case, it's entirely possible that his Zoan was intended for Chessmarimo and somehow was lost in transit to the castle.
Paramecium are the most common, but are generally held by people who serve in organizations and have employers with connections (Baroque Works, Marines, etc.), or pirates of significant rank. Even Buggy obtained his while apprenticing with Gol D. Roger, Luffy obtained his from Shanks (Yonkou). Even Robin isn't an exception, because her mother is technically a Pirate, with a wanted poster and all.