Yes, let's compare older movies which have only Batman or Superman in it and from a time where China was nothing to talk about with a movie from 2016, a time where we will get some billion sellers every single year and with Batman and Superman fighting against each other. As if such a clash between these two wouldn't get the interest of many more people as long as the movie would be good.
If movies like Deadpool could beat BvsS (in theory, it didn't release in China and has 100m+ less revenue because of this) you realize how "low" BvsS numbers are even if it will make a ton of money.
BvsS with a good quality as billion seller was a pretty sure bet, the numbers from release show this as well but then there was word of mouth and it dropped like a rock. Even the first Sunday already shows this, it dropped already so short after release and as longer the movie was out as more people told their friends that it's nothing they need to see.
The only good thing which happend to this movie was the first days WW before people could tell their friends to rather stay at home...that saved the movie, money form people who didn't know much about the quality^^
