I guess that's because it's not a surprise. This has come up before, and it's basically unavoidable with the way PyPI is designed to work: if you see an unclaimed name, you can put whatever you want there.
I see your point, but I don't think that it needs to be a surprise to be announced or made well-known. No one is surprised that Microsoft releases loads of patches every Patch Tuesday, but they still publicize it and make it well known and easy for people to find out about.