I think one issue is that people have different opinions on whether "ownership gets really tricky" is a common case or an edge case. Many people with unique_ptr experience seem to assume that Rust's owned pointer is more of the same and not really applicable when ownership is even slightly complex, but this is not the case. Rust's owned pointer is vastly more powerful than unique_ptr and in my experience (and in Rust compiler and Servo browser's experience) and "ownership gets really tricky" is an edge case.