Why do people tell you that they're going to block you or mute you? Why not just do it.. what's the point of telling me?

I was thinking about something that happened a long time ago after reading a question on here just now. Someone literally sent me a message to tell me that they liked me, but that my post were negative and so annoying that they were going to mute me for awhile. I forgot everything else she said, but it was really stupid. I don't know if she ever muted me, but I did block her after that. The thing is other than that I had no issue with this person. It was so random...