I think it's a valid criticism. Ownership, mutability, and thread-safety are not easy to abstract over and hide as implementation details in Rust. It's a side

I think it's a valid criticism. Ownership, mutability, and thread-safety are not easy to abstract over and hide as implementation details in Rust. It's a side effect of the fact that Rust actually cares about these and checks them strictly, but for users coming from eg Java that's a bit of a shock.