Nextdoor is a messaging platform too, even more so than AirBnB, but the difference is that they are taking steps to combat racial profiling on their platform. Steps like meeting with concerned parties in-person and having open dialogue with their user-base. They are even working with external parties to test some product ideas that they believe would help the situation (though it is acknowledged that it's impossible to completely eliminate something so deeply ingrained in a society and culture). [1][2][3]
I think there's a marked difference in attitude between the companies towards a problem they both face and just because Facebook or Big Company X ignore stuff like this doesn't mean it's ok for everyone to ignore it. A change in attitude alone is progress on these fronts and we should hold more of these companies accountable so that they at least try to do something. It's not their responsibility to eliminate racism, but I believe it is their responsibility to try to understand how and why something like this manifests on their platform and try to take steps to curb it.
It's not an easy problem by any means, but try is the key word here. More companies taking well-intentioned steps like this leads to learnings that can be shared across our industry.
[1] https://blog.nextdoor.com/2016/01/27/our-commitment-to-end-r...
[2] https://blog.nextdoor.com/2016/04/12/improvements-to-how-our...
[3] https://blog.nextdoor.com/2016/04/26/continued-improvements-...