Words matter. Meanings of words matter. Exactitude of speech and writing matters.
You can tell that most of the people throwing the word "racist" around (also homophobe, misogynist, sexist, privilege) don't really know what the word means.
Critical Theory believes that anybody who is "white", or who refuses to acknowledge the existence of SYSTEMIC racism (no one is seriously discounting individual examples of prejudice), or who will not disavow or apologize for their "whiteness", or fully embrace the godless Black Lives Matter political movement, is a racist and a white supremacist. To these people, you are literally evil incarnate, because you were born evil, if you are "white". They make their hatred of men, and the fair-skinned, and Christians, and heterosexuals very clear.
There is a word for people like this.
bigot: one who is strongly partial to one's own group, religion, race, or politics and is intolerant of those who differ.
- American Heritage Dictionary
They are bigots.
So when people start in with their hatred or disdain for "whiteness" or "white people", or any grouping of people deemed evil by this new religion of critical theory, it is acceptable to call them what they are.
They are bigots.
Words do matter, you notice how we embraced being called deplorables but when the same people call us nazis we don't respond with the same enthusiasm?
We understand what words mean, we also understand the difference between a regular American who disagrees with the democratic platform, and someone who gave people zyclon B showers.