But Jedi don't have to BE naive. That is one thing that kinda bugged me about the RepCom series. Not every Jedi is an emotionally stunted child with no knowledge of the outside world. They go out, they experience things, they HELP people, and most have a pretty good understanding of how things work. I agree that the whole "army of slaves" thing was a really big slip-up on the order's part and there are a lot of Jedi who are pompous, sanctimonious, naive, jerks, etc. But not all of them are like that. In fact, I'd argue a good portion of them AREN'T.
The fact is that Etain has no common sense, makes no effort to improve throughout the series in ANY aspect of her life (from being a weak Jedi to being a proper Mando), and doesn't seem to think about long-term consequences or how her actions will affect others (it borders on selfish sometimes). So, basically, Bella Swan.