Yeah, because the cash is all that matters...
The Transformers series and the Pirates of the Caribbean franchise make a lot of money too. I don't think anyone thinks of those movies very highly, do they? Big summer CGI blockbusters tend to make a lot of money, and MoS fit that bill.
Other than financially, how can MoS be considered a success? It was panned by the critics. A 56% RT score is nothing to be proud of...considering its lower than Spider-Man 3, X-men 3: The Last Stand, and Ang Lee's Hulk, which last time I checked, were considered massive flops...
Lets not forget that there are
26 comic book films rated higher including EVERY Marvel Studios film.
I honestly don't understand how people here consider it a success. It was terrible, but it made a lot of money. That doesn't make it a success, at least not to me.