Nextdoor has had enormous racism/bigotry problems. They have had to revamp a variety of their interfaces to minimize this problem. It's like they have to do A/B testing to minimize it. Real identity doesn't do anything to slow down the oblivious.
Could you provide some concrete examples? I've used Nextdoor regularly in three major US metropolitan areas, and I have yet to see anything like an "enormous racism/bigotry problem." If anything, I see sanctimonious neighbors calling each other racist at the drop of a hat.
51% of Murder and nonnegligent manslaughter is committed by about 7% of the US population. This is directly from Government data.
There are real biological factors identified for this discrepancy:
This allele you've identified as the genetic reason for white superiority is most common among Asian men.