Artists certainly are allowed to make films that only satisfy their own creative pursuits. But blockbusters—more than any other kind of film—are conceived of as a way to entertain and satisfy audiences (so they can make money). Modern spectacles feel like they're built to entertain and satisfy their filmmakers instead. They're not considering who their destruction is actually for anymore. They're just doing it. Or, as Vulturewrote, when it comes to destruction porn, "No one necessarily asks for it; it just kind of happens."
My own reservations about how this unfolded in Man of Steel are actually not what's most on my mind when I think about this.
One thing I've noticed about myself vs. other writers with a Web / social network presence is how much more explicit and candid many of them are about their work while it's still being produced. E.g., Twitter updates about word counts or editing status, or even posting the whole thing to their blog incrementally (my friend Scott Delahunt has been doing this with his Lethal Ladies and Subject 13 projects). I don't think these approaches are bad or wrong, just that I've found that they're not the approaches I prefer to take.