Why should the hard work, or lack of it, of a player even come in to it though? And more to the point, how do we even know how hard one player has worked compared to another? We don't know anything about it really other than platitudes given by employers to their most powerful and skilled players (which, as you pointed out, Ronaldo is).
Football is entertainment, and just like in art/music most people are inclined to be more impressed by sheer natural talent in full flow than they are endeavour - otherwise Darren Fletcher would be winning the ballon d'or, as I imagine he's put in more 'sheer hard work' in his recovery than Ronaldo could even imagine.
In an increasingly automated world ruled by rigid technology, more plastic than organic - the 'super proficient', wax work looking, self celebrating 'machine' that is Ronaldo is gonna leave some people cold.
Messi plays with a freedom and fluidity that, at his best, is actually cathartic to watch - the 'little guy' running free and mocking the 'organisation' of the defence - it offers people a feeling of exhilaration. And it's more aesthetically pleasing while at the same time being more productive, a feat that is really the pinnacle of any kind of entertainment.