I was not aware of this issue. That is heart breaking. The cPython one is especially painful to see. Anyone have any thoughts on how to stop the minimum effort PR influx during this month? Thanks OP for spreading awareness!
It looks as if this year only repos with the topic "hacktoberfest" or PR's with the the tag "hacktoberfest-accepted" participate, so this should limit the amount of spam. Source: https://hacktoberfest.digitalocean.com/faq
It was the case last year too. It didn't prevent the PR spam though -- many repos didn't opt in and still received a lot of trash PRs.
Putting the burden on the maintainers to label PRs as spam is a terrible idea. Digital Ocean is fueling an unsustainable culture here.