Personality certainly plays a big part. Jones and MacDonald are both odd characters at least in the spotlight.
Fans tend to like conventional, relative to this industry. That means Chuck running around screaming like a lunatic when he got a KO, BJ licking his gloves, JDS slashing his chest etc is all fine and actually gets people pumped up. But straight up smarmy cockiness is very rarely appreciated. Ali shuffles fall into thi category, especially during a fight in which one of the long term legends of this sport is officially being pushed aside for good.
John8204 makes a good point about the lifecycle too. Rashad Evans is the prime example of a fighter initially hated and then cheered on in most fights. His smarmy cockiness wasn't liked and nor was he, but now he's earned his stripes and is a popular fighter and HUGE ppv draw. Despite all Jones' PR
mistakes and UFC 151 mess, I think he'll reach the same stage as Evans in a few years. It might take a humbling loss to do it though.