If youre comparing the relative popularity of films (how one connected more with audiences than another, how one tapped into the zeitgeist more successfully than another) then box office is a reasonably good yardstick. A movie that earned $150M obviously connected better than a movie that earned $50M. More precisely, divide the gross by the average ticket price and you get units sold - an apples-to-apples comparison (which is how book and Top 40 music sales are measured).
But under this type of sociological analysis (box office as an indicator of cultural resonance), budgets and profitability become irrelevant. Subtracting the production budget from net profits doesnt retroactively affect the number of people who actually saw the movie.
Yes, but you must also account for the resources a film creator has. Say for example, if Christopher Nolan's "big break" movie was Inception rather than Memento, and created on the same budget as Memento, do you think as many people would have gone to see it as the real version? I certainly don't, because it wouldn't have had the same financial backing of the movie studio.
The ability for a film to do well financially is quite often intrinsically linked in how much financial backing it received and the studio always wants the films to make them money, Superman Returns didn't, it lost money (someone else quoted the movies number against budget and on average the studio gets around 55% of that).
Not to mention the fact the film was written into a corner narratively, having only a relatively good reception and any potential sequel being delayed by Singer.
It was by no means a disaster, but a sequel was never likely, gross and budget were just two of a few reasons.
Man of Steel won't have those problems, but it will have to compete with a bad opening position, and being a relatively small fish in a much bigger pond. But I forgot it will have a 3-D boost, I now expect numbers a bit better than Batman Begins.