There's really no reason why diffuse harms should not be criminal while focused ones should (arguably, diffuse harms are less able to be addressed by individual action through the civil justice system, so outside of focused harms where the victim is unable to pursue action after the crime, like murder, diffuse harms are the most important for government to address directly.)
OTOH, there's often a lot more disagreement over whether what some people perceive as a diffuse harm actually is a harm.