Because they’re both complicated languages, but for different reasons. Rust didn’t really solve memory safety, it just pushed all the complexity into the type system. If one was struggling with memory errors in C++ that’s nice. If one was using Java, that still sucks.
Furthermore some programmers really like complicated languages like Rust, Haskell, etc others like straightforward languages like Go, Python, etc.
Furthermore some programmers really like complicated languages like Rust, Haskell, etc others like straightforward languages like Go, Python, etc.