Other cultures' racism doesn't excuse your own culture's racism. The argument that someone else was/ is racist is null.

The excuse of transgressors is often "yes, that's how it was, but hey, you haven't seen the changes we've made- you're just out of date". Just as politicians always ask if you've seen the latest statistics. Of course you haven't- and often those asking the question know that they are in fact no different from the previous set.

And of course virtually everybody has racist reactions at some point. Does that excuse racism as an ongoing institutionalised practice?