Depiction of superstition

Does anybody else feels like superstitions failing and bringing suffering was a recurrent theme in the movie? Example: the belief that you cannot get pregnant if it is your first time, Juana's failed abortion attempts, Maria getting bitten by a snake as soon as she steps on the fields? This last scene in special gave me this impression because of the long scene depicting the preparation ritual, the loud praying during the scene and how immediate the snake attack was.

It seems that the plot was moved by the characters gullibility causing them to make bad decisions, instead of external forces (perhaps the snakes count?). Do you think that was a conscious decision of the filmmakers?

I think it is sad that I have add this, but here it goes: I'm not blaming indigenous people/culture for their suffering neither am I calling them dumb and, yes, I'm aware of the sociological causes of those problems.

Thanks!