That's because white racism does impact the mental well being of black people. That's a fact. And it must be considered when you talk about people of color. You don't face it every day of your life so you dismiss it, because you don't know how it feels when you are subjected to it..
“Bryant-Davis and Ocampo (2005) noted similar courses of psychopathology between rape victims and victims of racism. Both events are an assault on the personhood and integrity of the victim. Similar to rape victims, race-related trauma victims may respond with disbelief, shock, or dissociation, which can prevent them from responding to the incident in a healthy manner. The victim may then feel shame and self-blame because they were unable to respond or defend themselves, which may lead to low self-concept and self-destructive behaviors. In the same study, a parallel was drawn between race-related trauma victims and victims of domestic violence. Both survivors are made to feel shame over allowing themselves to be victimized. For instance, someone who may have experienced a racist incident may be told that if they are polite, work hard, and/or dress in a certain way, they will not encounter racism. When these rules are followed yet racism persists, powerlessness, hyper vigilance, and other symptoms associated with PTSD may develop or worsen (Bryant-Davis & Ocampo, 2005).”
“On occasion, the emotional weight of racism can lead African Americans to engage in maladaptive coping, such as remaining in denial, engaging in substance use, aggression, self-blame – even in extreme cases suicide (i.e., Black Lives Matter activist Marshawn McCarrel) and terrorism (i.e., Dallas shooter Micah Xavier Johnson). These responses are harmful and lead to negative, long-term consequences.”
Ryan C.T. DeLapp, MA, and Monnica T. Williams, Ph.D., “Proactively Coping With Racism, Getting back to our lives in the aftermath of racial violence in the media.”, July 18, 2016,
www.psychologytoday,com
So until whites can understand the complete damage racism causes, you won't understand how I can say that racism is part of the cause. Racism is a socially unacceptable behavior, and the results of that behavior when it is imposed upon people for a long duration, will at times create unacceptable behaviors in return.