The claim is uncomfortable because the word "racism" has a connotation in some circles of basically being a klansman (or at the least of actively hating people

The claim is uncomfortable because the word "racism" has a connotation in some circles of basically being a klansman (or at the least of actively hating people based on nothing except for their race). Admitting said claim for those people does not feel like acknowledging the system we live in against their will or that they have unconscious biases. It feels like acknowledging a serious character defect, worthy of ostracism, being fired, and possibly having a mob show up at your house. Now, I'm not a prescriptivist. I acknowledge that language evolves, but it does not evolve the same way in every place at the same time. It tends to evolve in a particular place and spread out from there. The particular definition you're using has not spread to the entirety of society yet. Your pitch could really benefit from some localization to the various sub-dialects of the english language if you'd like less push back in the future.