I don't think anyone said he was stealing for a dozen years. Once again, what I heard was that JJ fealt that Barry was a friend. When people would tell JJ that Barry was a screw-up, JJ stood by Barry. Bad move from a business standpoint instead of talking to him, but partly understandable from a friend standpoint. Finally, JJ had no option but to talk with him, and that's when the crap really started. Barry's poor business skills turned into Barry's poor stealing skills and a purposeful destructive nature instead of just incompitence. NOTE: I only heard this from someone in the know, but still can't prove or disprove it. I happen to believe it, but that is me. It tends to follow the line of the story that I believe. Those of you that believe Barry to be the victim here will, of course, not believe this and that is fine too.
But, the short answer to the question above, absurd as I think it is from a reality standpoint, is that JJ considered Barry a friend and trusted him. Sometimes, that makes us do really stupid things.
Chris