I have learned both and agree with this statement. I think that Rust is harder to learn if you've only worked with high-level, GC languages, and don't have a background doing lower-level programming in C/C++/Obj-C, as well as some experience with functional languages.
Going from something like Java or Python to Rust, one would have a lot to learn.
Going from something like Java or Python to Rust, one would have a lot to learn.