What do people even KNOW about "taboo" on ANYTHING in general.

Are there those that don't know it or think too much of it and give it importance? Why does taboo say have to exist on sex and/or bodily fluids but not on violence, murder, beatings or even certain words and attitudes? And does any or all of it MATTER and is it all always CORRECT and REAL or a matter of perception? Cheers.

After watching this movie, I got the impression haha, that this film "Sweet Movie" (1974) wanted to question audiences along those lines as well.