The attempt to redefine racism away from the dictionary definition into the "systemic privilege" one is, imo, an attempt to remove the intensely horrible associations with actual racism, to minimize its harms, and to provide a socially acceptable avenue for its practice.

The only reason white people enslaved back people was because they had the opportunity. Does that make it okay? Absolutely not. Does this absolve us of trying to make it right? Absolutely not.
But also white people historically have not had a monopoly on racism and slavery.

For example: Liberia - a country in Africa formed by black people who left America in the 1800s to escape white supremacy. They made their own country and then promptly enslaved the native population.

to clarify because people are uncharitable: no don't actually think there was a random 'u different i hurt now' urge. There was a lot of incentive to do this (land, money, labor), and the different race (and culture) made this socially permissible.