@Reckoner: Yeah, Enishi doesn't really have anything else going for him, and what you pointed out (that he walked so foolishly into the mistake) may or may not have been the main flaw in how they tried to execute Enishi's character growth. I'll have to think about that some more, since I'm not sure where exactly his character went wrong.
So I agree with you that Enishi is not the most compelling character, but I don't think it's because he fails at everything, including business savvy and common sense. I don't think you have to be good or even halfway decent at anything at all to be a good character in a story. You can probably think of at least one protagonist you like who falls into this category:
http://tvtropes.org/pmwiki/pmwiki.php/Main/FailureHero. And it's not like you could take every character from that category and make them good/better at something and suddenly they'd be more compelling. There's something else at work here.