Being able to disregard being called "cracker" is itself a form of white privilege. As a white guy, I don't have to care if some black person expresses hatred against me because I have power that they do not (e.g. they're not likely to act on their hatred because if the police are called they're likely to take my side, etc.). The implied threat is not credible.
In contrast, black people do not have the freedom to ignore white people calling them the n-word, because historically that has been accompanied by a real risk of attack. The likelihood may have waned over the years, but that implied threat remains credible. (That goes double for the fact that, as casual/mainstream use of the word has fallen out of favor, those still willing to use it are all the more extreme/violent-tempered.)
THIS!!! THIS IS WHY YOU NEED EDUCATION AND SAFETY! PEOPLE WANT TO LEARN AND DO BETTER!
Let me add one. People that don't look like us think before they speak in meetings. They are scrutinized constantly and often afraid. We can ask a colleague "hey not straight white guy, you're interested or expert in XYZ, and haven't shared your input, what do you think?"
This is exactly how systemic racism works. White people weren't kept as slaves and called 'cracker' as a label. Black people were kept as slaves and called the N word as a label. The implication, via the word, is that they were less-than-human. We're just about back to the time period where lawmakers openly use the N word again. I'm in Canada, yet even from here I can see it happening, and it's terrifying for me, so I can't imagine what it's like for American people of colour, or women, or 2SLGBTQIA+, etc.
If you are one of those people, whomever is reading this, just know you have allies.