Checking on your comment history, you seem like a reasonable person, with whom i probably agree on many issues. I agree with nearly everything you have said. However, since i know you're american, just like me, allow me to try to give my perspective on why your statement on white people, writ-large, is problematic:

Every single person on earth is hardwired to discriminate against "the other". You, me, Trump and <insert person you don't find reprehensible here>. This instinct toward petty tribalism is the single greatest challenge we currently face as a species (aside, perhaps, from the fact that we're allowing industrial capitalism to actively boil our planet).

Can you not see how the unmeasured response of saying "people with this color of skin have this problem" is, inherently, not just problematic, but actively defeats the purpose of what you're trying to say? This isn't the same thing as a positive statement like "black lives matter". Yes, of course "all lives matter", but clearly the fact that black lives matter needs to be explicitly pointed out. However, saying that "black lives matter" is not claiming anything negative about any person based on an immutable trait.

Consider the following statements common here in the US, each of which is something you should find reprehensible. In each case, consider the immutable trait, and what libelous problem is being inherently associated with that group of people:

1. "Mexicans/Colombians have a drug problem"
2. "The Chinese have a genocide problem"
3. "Black people have a crime problem"

For each of these, a portion of the people with that immutable trait definitively do have that problem. There are Mexican and Colombian cartels. The Chinese government is perpetrating a genocide against an ethnic minority. Some black people are criminals. However, when you paint with such a wide brush, you don't just perpetrate discrimination against the whole group of people who don't get to choose where they were born, or the style of their governance, let alone the color of their skin. You actively alienate any people in each group who might agree with the existence of a problem, and you also ignore any context which shows the greater, actual problem:

1. The systems of drug regulation have failed.
2. Dictatorial regimes perpetrate genocides as easily as signing a piece of paper.
3. Crime is a problem everywhere, regardless of skin tone, as are its underlying causes of poverty and lack of opportunity.

Obviously, each of those earlier statements (especially the one about black people. That one hurt to write) is deeply flawed, and utterly unproductive. Anyone painting an immutable trait as having a specific problem (aside from genetic problems) is inherently engaging in that same alienation, that same othering, as the people they find so reprehensible. Everyone has a moral duty to work toward ending the issues which plague our civilisation, but saying "you have a racism problem" not only misses the point entirely, but actively makes the problem worse.

I have no problem with calling out discrimination against a group of people, but making a statement like "men have a domestic abuse problem" is inherently unproductive and problematic, and sounds like nothing but picking a fight. "There is a serious problem with white people discriminating against people of different skin tones." Vs. "White people have a racism problem. Full stop."

In fact, I wouldn't even take issue with the statement "We have a racism problem caused by white people". Or "among white people". That's still painting with a wide brush, and is still problematic, but it isn't directly implying that every single person with white skin is perpetrating racist acts.

Anyone engaging with the democratic party must contend with the fact that the leaders of the party are actively abetting genocide. But the fact that you were born with white skin does not imply that you need to engage with the problem of racism. EVERYONE needs to engage with the problem of racism, and bringing an immutable trait into it to call people out is inherently problematic.