Hi there @ThejoyofNC.
It wasn't really a case of 'knowing it was happening and letting it carry on'. The thread you refer to in itself did not break Talk guidelines. We take racism very seriously but that doesn not mean that certain topics can never be discussed at all; we would always look at the thread as a whole and delete any posts that did constitute racism or break our guidelines in other ways.
In this case, we were receiving a huge number of reports across a period of several hours and there were many other threads that also required pretty immediate attention. During that time we deleted many posts on the thread and behind the scenes had taken other action, including banning some posters and contacting others off the boards.
While reports like this are coming in, we're always keeping an eye on whether the balance of a thread has tipped enough to require it being removed completely. In this case, we'd say that balance was nearing tipping point anyway when the OP asked that the thread be removed completely, and at that point we agreed it was for the best for it to go.
We understand that it may feel like you are reporting and not much is happening, but behind the scenes there is a lot more than that going on. We'll always delete racism and did so here, but where a thread in itself is not racist, we try to allow a conversation to happen while moderating in hopes that the thread can remain on track. In this case, as we say, it only became unsalvageable a good few hours in, and at that point we made the decision but we don't think it benefits anyone or changes hearts and minds for us to delete threads before they hit that (sometimes delicate) tipping point.
We hope that explains things a bit further. And we hope it also goes to show that your reports really are useful. While we moderate by our Talk guidelines, it's often the reports coming in that allow us to see when a thread starts to tip over into deletion territory and it looks like that was certainly the case last night, so thank you.