Same principle behind Python's crippled lambdas.
Yeah, it's a shame for Python. I am extremely impressed that Java 14's switch expression ( https://openjdk.org/jeps/361 ) is a generalization of the switch statement (since Java 1.0); it's like they took a page from Rust's language design. I have found the switch expression to be quite useful in my work.
(I do realize that there was opposition on this, but that the Clearly Wrong side won out is baffling.)