Why standing with the hands closed in front below the waist is not considered to be a good body language?

Generally, having the hands closed (fists) can be taken as a defensive stance, that can come from short temper or fear.

It is a gesture that draws attention of people to one`s private parts and maybe taken as reflection of the state of the penis or vagina...can be highly misconstrued for an uncontrollable sexual arousal and that is embarrassing to show in public.