I don’t think these qualify as “Mass Shootings” according to the normal definition of one shooter and mass casualties. Different type of perp and dynamic. They should not be conflated. Your point is correct in that they are sort of ignored, but they are sometimes used in the same statistic stats to inflate the number of so called “Mass Shootings” to get laws passed on fear at the same time they often ignored as they are more indicative of gang violence.