Because many US fans think the boxing world revolves around the US. It doesn't to the degree it once did. So they're having a tough time with the current reality :-( That's the main one. Too much risk for the reward. But of course Joe C gets all the blame that these fights didn't happen years ago.
This seems pretty plausible to me.....I always had a feeling that Joe lacked a little confidence. Why else did he keep re-signing with Warren when he now says he wasn't happy with the service? Because he wasn't confident enough to find his own way maybe? Theres nothing wrong with being a late bloomer though.