I feel like I could respond to this post on two levels. The first would be a deep dive into philosophy and is anything truly objective, is there objective morality, is it all just human constructs and enculturation, etc., etc., etc. This would result in about elebenty billion posts going round and round that would not ultimately resolve anything because humans have pondered these same questions for eons without a definitive answer (although I would find it fun, ha ha.)
On a more practical level though - whether or not there are objective moral codes out there - I think the issue at the moment is that our whole paradigm surrounding racism changed very, very fast, in historical terms, and not everybody was on board with those changes. Whether or not a society's moral codes are actually 'objective' is a philosophical debate, but I agree that in a smoothly functioning society, they should more or less seem objective to the vast majority of the members. Having stores only work if pretty much everyone thinks to themselves "stealing is wrong". Traffic lights only work if pretty much everyone thinks "red means stop". Having a government only works if everyone accepts it as a legitimate authority. Etc. That's not to say that there's no room for debate on important issues but we do have to have a baseline of shared understanding. Right now, depending on your age, geographical location, socioeconomic status, etc., people have very different ideas about what constitutes 'racism'. One person might see a 'micro agression' as true racism, while another person sees calling someone racist based on micro aggressions as a symptom of a dangerous 'cancel culture'. Further complicating this is the fact that we have paid relatively more attention to race relations in the past few years, and relatively less to class relations, and they are both very important. That attitudes about these new norms tend to break down along class lines doesn't help the situation at all, especially in an era of ever escalating income inequality.
How all of this will shake out, I don't know. It will resolve one way or another, but how exactly is anybody's guess. There will be plenty of articles and books speculating on this theme, no doubt. As far as whether or not things "should" be this way - I would say that this is neither here nor there at this point. Maybe people shouldn't be divided, but the fact is that they are divided, and that's just the way it is at the moment, there's nothing you or I could say here that would change what is already a reality.