The suggestion above that when you recommend the Mudcat you give a link to a particular thread that is relevant to the person you are recommending it to instead of to the forum makes a lot of sense. Gives the newcomer a taste of the Mudcat when it tastes good.
But I think you'd need to be pretty jaundiced to think the Mudcat is full of racists just on the basis of those threads, which I hadn't even opened before reading this one. What comes across much more clearly is that racism is not welcome here.
Moderation yes, moderating no. There can be a point when free speech runs up against more important values, but we're a long way from that point and I hope always will be.