I don't know, maybe you're right, but I don't think you really have an idea of who works harder. How do we know that Jay isn't the harder worker? How do we know that Jay isn't a student of hitting? Because Joey gives better answers in interviews? What would Joey have looked like at age 22 in the big leagues? Would he have been slow to make adjustments? Yes, talent fades, Jay's got about ten years before it starts fading though. I don't like the idea that Jay's already getting the label of "not an exceptional worker" when none of us really know how hard any of these guys work.
Relying on anecdotal evidence here, and there's plenty to suggest Votto's work ethic is exceptional, while there is little, if any, that indicates the same about Bruce. Bruce had never really experienced adversity until he hit a rough patch in the bigs last year, so its understandable that he might think the game comes easy.
Perhaps a more palatable argument for you would be to point out, as others have noted, the plate approach and swing mechanics of Votto -- partly a result, I would say, of his study -- are superior to Bruce's. Unless Bruce makes adjustments -- and he has not shown much of a knack for it yet -- he'll never see the level of major league performance Votto's putting up right now, in my opinion.