As a white person brought up in the racist south in the 50's-the present, I must agree with you.
Racism as a stance or belief or underpinning is as simple as any belief system gets: that all members of a particular race are inferior because of their membership in that race.
Now there are multiple errors in that "belief," and I'm sure I don't need to detail them here. But when someone says that "X is complicated," most typically they mean either of two things:
1. That the assertion X can't be reduced to a simple formula or binary
or
2. That they want to ignore the obvious truths in the assertion X--they want to demur.
Clearly the second option underlies the demurrals of racists.
I'm hoping to post about the upcoming US Supreme
Couirt deliberation about affirmative action in higher education decisions. I find your post about reverse racism most helpful.