WB admitted they consider MOS to be a bit of a dissapointment because it didn't make TDK/TDKR money. As in make at least $1 billion. Anyone who has a bit of common sense and some basic knowledge on how the industry works knows 100% there is no freakin' way MOS could have done much money. Much like every other CBM reboot, it carried the burden of being a reboot and being the first film after a bad film with the same character. All reboots had that because the new franchise first has to earn the trust of the audience. Batman Begins did not make $1 billion either. It is always the second film in a rebooted franchise that proves whether or not the first film and the reboot overall was a success and a good idea in the first place.
On top of carrying the reboot burden, MOS practically had zero marketing up until April 2013 (excluding the first two trailers), whereas TDK had a lot of viral marketing since very early on. It also only had about one or two free weeks before other big summer blockbusters came along and had to compete with it.
When you consider all that, the amount MOS made is completely realistic and if anything, it proves that Superman has potential on the big screen with today's audience.
The expectations WB had for MOS were absolutely ridiculous given the factors. They set such a high bar that even Batman wouldn't have reached had he been in the same shoes that Superman was in MOS, or would have at least had a bit of trouble reaching. They gave Superman a small toothbrush and asked him to clean the entire mansion with it in a limited amount of time. Then when Superman wasn't able to do it, they were confused as to why he didn't succeed (not the best analogy, but you get the point).