If you really want to know, it's because I am an old lady who has worked with a lot of people of many backgrounds over the years, and I can imagine quite a few of them sharing that post that Peggie did, while also knowing those people in their working lives just got on with the job and treated everyone equally, and I have never heard any evidence that Peggie did not do this as well.
So while I think the jokes she shared are vile (and that is a word I try to avoid because it's become almost meaningless), I've seen far worse racsim in practice from people who would not be caught dead sharing the jokes, and I've seen far more acceptance and support in practice from people who take joy in saying things they know will shock.
So, in short, I think there is far too much glee being exhibited by people who want an excuse to condemn Peggie when they have never even bothered to look at whether people on their own side are doing or saying the same thing.