I've read some of Foucault's work, and this is my honest take:

He was an actual communist who thought of everything in terms of "the struggle." Scientists (etc.) are respectable? They must be oppressing people.

https://en.wikipedia.org/wiki/Michel_Foucault

A large portion of philosophers are “actual communists”, since they actually read Marx

EDIT replying to sub comment (I am once again rate limited)

Indeed he literally wrote an essay called “On the ruthless criticism of everything existing” which argued against the French socialists who came up with prescriptions rather than solid critiques. Marxism isn’t about communism, it’s about criticising capitalism. That’s why he spent so little time talking about communism. That would be like a slave or a serf wondering what might come next. A strong scientific (in the German sense) critique was his project

Marx is good when it comes to explaining things. Less so when it comes to prescriptions on how to fix them.

Foucault lived when the actual Nazis were in power and saw the rise of eugenics, so I'd bet that has more to do with his relating power and the course of science than "scientists are respectable ergo oppressive". Iirc he was also fairly clear about how his analyses were rooted in observation of actual occurrence, and not an attempt to divine the essence of the idea of science and power.

context, man. it matters.

> rooted in observation of actual occurrence

So by observation of actual occurrence Foucault means ignoring the entire history of science radically improving living conditions and extending lifespans for the previous centuries and instead conflating it with Nazis? That explains a lot.

Orwell was a generation ahead of Foucault, but he lived through many of the same events. Unlike Foucault, he drew the correct conclusions about them. His work will still be read when Foucault is just a footnote.