There is YES a HUGE difference between MASS executions and that of GANG violence. Ironically the solutions are possibly more closely link than that of the foundation of the problems.
One is a social problem that can be identified and solved. The other is an ideology that takes on a life of its own and yes again, can be solved with social awareness. However when you have the LEADER of the country, inspiring young and old minds alike, that THE SOLUTION IS VIOLENCE that is a whole different thing than 300 black being killed in Chicago being compared to almost 300 mass murders over this past year.
In fact the social issues contained within a social specific group, while devastating can more quickly and easily be brought towards solvable actions than that of an ideology being planted by the very source that holds the key to actionable solutions.
Finally, you are absolutely correct when you say, Black Youths dying, is just as painful and devastating to the families and or friends and yes, should also be to the country. However when you have an ideology that basically states that my Dead is deserving of justice and your dead is better off dead, there is simply no comparison to
A) the devastation that has long been occurring at the hands of young White males
B) Now a leader with the ideology that justifies their violence.