Ditto (3D, too).
That said, I think the name helped to kill the movie. It ought to have been called Barsoom.
Those who’d read the books would know what to expect... and those who hadn’t would have thought it some sort of fantasy movie (which isn’t too far off the mark.)
I remember hearing a movie was coming out, called “John Carter” and for me there was no clue as to what is was about or like. Even some promo photos I don’t recall anything distinguishing. So yes, bad marketing. You only have a few seconds to create an impression, and the impression they left was “a movie about some guy”.