Why is humour such a problem on SW?

I've just been blocked for trying to joke with another member who has previously posted that she is "very open-minded" and doesn't judge people based on what they've done in the past. So why would she block me for trying to joke with her? The last thing she said before blocking me was "What's your problem?". Indeed, what is my problem? How is any of this even a problem? How is having a sense of humour a problem?