Is Beet really that popular? It never got me that's for sure. Mind you the only reason why 4Kids licensed One Piece is due to it's immense popularity, I don't think it really mattered whether or not they had to edit the living hell out of it, the only really saw it as a cash cow. Face it most companies are like that, they look to what will bring in a profit, and sometimes don't really think ahead a whole lot.
As for another anime, I dunno how bout an actual kiddy show? Anpanman, oh god I really wanna see an episode of that. It's about a hero whose head is made out of anpan which is some kind of bean filled pastry or something, someone correct me if I'm wrong. I read about the show like a good number of years. Anyways Anpanman helps starving kids by letting them eat a part of him.
Prince of Tennis would've worked, it was quite popular in Japan so I dunno why they didn't look into aquiring that. Well I guess it's harder to market a sports anime let alone a tennis one when weighing it out against a pirate anime. 4Kids also probably thought of Pirates of the Carrebien (sp is so off), and with all the success that it got, they figured "let's cash in on it!"